Composite device and program

ABSTRACT

A composite device with a high security level is provided. A composite device capable of inhibiting unauthorized use favorably is provided. The composite device includes a control portion, a detection portion, an authentication portion, and a memory portion. The detection portion has a function of detecting a touch and a function of obtaining first fingerprint data of a finger touching the detection portion. The authentication portion has a function of executing user authentication processing. The memory portion has a function of retaining second fingerprint data registered in advance. The control portion has a function of bringing a system into an unlocked state when the authentication portion authenticates a user and a function of comparing the first fingerprint data obtained by the detection portion and the second fingerprint data when the detection portion detects a touch, and bringing the system into a locked state in the case where those data do not match.

TECHNICAL FIELD

One embodiment of the present invention relates to an electronic device.One embodiment of the present invention relates to an authenticationmethod. One embodiment of the present invention relates to a displaydevice. One embodiment of the present invention relates to a program.

Note that one embodiment of the present invention is not limited to theabove technical field. Examples of the technical field of one embodimentof the present invention disclosed in this specification and the likeinclude a semiconductor device, a display device, a light-emittingdevice, a power storage device, a memory device, an electronic device, alighting device, an input device, an input/output device, a drivingmethod thereof, and a manufacturing method thereof. A semiconductordevice generally means a device that can function by utilizingsemiconductor characteristics.

BACKGROUND ART

In recent years, information terminal devices, for example, mobilephones such as smartphones, tablet information terminals, and laptop PCs(personal computers) have been widely used. Such information terminaldevices often include personal information or the like, and thus variousauthentication technologies for preventing abuse have been developed.

For example, Patent Document 1 discloses an electronic device includinga fingerprint sensor in a push button switch portion.

Reference Patent Document

-   [Patent Document 1] United States Published Patent Application No.    2014/0056493

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

An object of one embodiment of the present invention is to provide acomposite device with a high security level. Another object is toprovide a composite device capable of inhibiting unauthorized usefavorably. Another object is to provide a novel composite device.

Note that the description of these objects does not preclude theexistence of other objects. One embodiment of the present invention doesnot have to achieve all these objects. Objects other than these can bederived from the description of the specification, the drawings, theclaims, and the like.

Means for Solving the Problems

One embodiment of the present invention is a composite device includinga control portion, a detection portion, an authentication portion, and amemory portion. The detection portion has a function of detecting atouch and a function of obtaining first fingerprint data of a fingertouching the detection portion. The authentication portion has afunction of executing user authentication processing. The memory portionhas a function of retaining second fingerprint data registered inadvance. The control portion has a function of bringing a system into anunlocked state when the authentication portion authenticates a user, anda function of comparing the first fingerprint data obtained by thedetection portion and the second fingerprint data when the detectionportion detects a touch, and bringing the system into a locked state inthe case where those data do not match.

One embodiment of the present invention is a composite device includinga control portion, a display portion, an authentication portion, and amemory portion. The display portion has a function of displaying animage on a screen, a function of detecting a touch on the screen, and afunction of obtaining first fingerprint data of a finger touching thescreen. The authentication portion has a function of executing userauthentication processing. The memory portion has a function ofretaining second fingerprint data registered in advance. The controlportion has a function of bringing a system into an unlocked state whenthe authentication portion authenticates a user, and a function ofcomparing the first fingerprint data obtained by the display portion andthe second fingerprint data when the display portion detects a touch,and bringing the system into a locked state in the case where those datado not match.

In the above, the display portion preferably includes a plurality ofpixels. In that case, it is preferable that the pixel include alight-emitting element and a light-receiving element, and thelight-emitting element and the light-receiving element be provided onthe same plane.

In the above, the light-emitting element preferably has a stacked-layerstructure in which a first electrode, a light-emitting layer, and acommon electrode are stacked. The light-receiving element preferably hasa stacked-layer structure in which a second electrode, an active layer,and the common electrode are stacked. In that case, the light-emittinglayer and the active layer preferably contain different organiccompounds from each other. Furthermore, it is preferable that the firstelectrode and the second electrode be provided on the same plane to beapart from each other and the common electrode be provided to cover thelight-emitting layer and the active layer.

Alternatively, in the above, the light-emitting element preferably has astacked-layer structure in which a first electrode, a common layer, alight-emitting layer, and a common electrode are stacked. Thelight-receiving element preferably has a stacked-layer structure inwhich a second electrode, the common layer, an active layer, and thecommon electrode are stacked. In that case, the light-emitting layer andthe active layer preferably contain different organic compounds fromeach other. Furthermore, it is preferable that the first electrode andthe second electrode be provided on the same plane to be apart from eachother, the common electrode be provided to cover the light-emittinglayer and the active layer, and the common layer be provided to coverthe first electrode and the second electrode.

In the above, it is preferable that the light-emitting element have afunction of emitting visible light, and the light-receiving element havea function of receiving the visible light emitted from thelight-emitting element.

Alternatively, in the above, it is preferable that the light-emittingelement have a function of emitting infrared light, and thelight-receiving element have a function of receiving the infrared lightemitted from the light-emitting element.

Another embodiment of the present invention is a program that isexecuted by a composite device including a control portion, a detectionportion, and an authentication portion. Here, the detection portion hasa function of detecting a touch and a function of obtaining firstfingerprint data of a finger touching the detection portion. The programof one embodiment of the present invention includes the following steps:a step of bringing a system into an unlocked state in the case where theauthentication portion executes user authentication and authenticates auser, a step of obtaining the first fingerprint data when the detectionportion detects a touch, a step in which the control portion comparesthe first fingerprint data and second fingerprint data that isregistered in advance, a step in which the control portion executesprocessing in accordance with the touch in the case where the firstfingerprint data and the second fingerprint data match, and a step inwhich the control portion brings the system into a locked state in thecase where the first fingerprint data and the second fingerprint data donot match.

Effect of the Invention

According to one embodiment of the present invention, a composite devicewith a high security level can be provided. A composite device capableof inhibiting unauthorized use favorably can be provided. Alternatively,a novel composite device can be provided.

Note that the description of these effects does not preclude theexistence of other effects. One embodiment of the present invention doesnot have to have all of these effects. Effects other than these can bederived from the description of the specification, the drawings, theclaims, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a structure example of a device.

FIG. 2 is a diagram showing a performance method of a device.

FIG. 3 is a diagram illustrating a structure example of a device.

FIG. 4A to FIG. 4D are diagrams illustrating structure examples of anelectronic device and examples of performance methods thereof.

FIG. 5A to FIG. 5C are diagrams illustrating structure examples ofelectronic devices.

FIG. 6A, FIG. 6B, FIG. 6D, and FIG. 6F to FIG. 6H are diagramsillustrating structure examples of a display device. FIG. 6C and FIG. 6Eare diagrams illustrating examples of images.

FIG. 7A to FIG. 7D are diagrams illustrating structure examples of adisplay device.

FIG. 8A to FIG. 8C are diagrams illustrating structure examples ofdisplay devices.

FIG. 9A and FIG. 9B are diagrams illustrating structure examples of adisplay device.

FIG. 10A to FIG. 10C are diagrams illustrating structure examples ofdisplay devices.

FIG. 11 is a diagram illustrating a structure example of a displaydevice.

FIG. 12 is a diagram illustrating a structure example of a displaydevice.

FIG. 13A and FIG. 13B are diagrams illustrating structure examples of adisplay device.

FIG. 14A and FIG. 14B are diagrams illustrating structure examples ofdisplay devices.

FIG. 15 is a diagram illustrating a structure example of a displaydevice.

FIG. 16A and FIG. 16B are diagrams illustrating structure examples ofpixel circuits.

FIG. 17A and FIG. 17B are diagrams illustrating a structure example ofan electronic device.

FIG. 18A to FIG. 18D are diagrams illustrating structure examples ofelectronic devices.

FIG. 19A to FIG. 19F are diagrams illustrating structure examples ofelectronic devices.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments are described with reference to the drawings.Note that the embodiments can be implemented in many different modes,and it is readily understood by those skilled in the art that modes anddetails thereof can be changed in various ways without departing fromthe spirit and scope thereof. Thus, the present invention should not beconstrued as being limited to the following description of theembodiments.

Note that in structures of the invention described below, the sameportions or portions having similar functions are denoted by the samereference numerals in different drawings, and a description thereof isnot repeated. Furthermore, the same hatch pattern is used for theportions having similar functions, and the portions are not especiallydenoted by reference numerals in some cases.

Note that in each drawing described in this specification, the size, thelayer thickness, or the region of each component is exaggerated forclarity in some cases. Therefore, they are not limited to theillustrated scale.

Note that in this specification and the like, the ordinal numbers suchas “first” and “second” are used in order to avoid confusion amongcomponents and do not limit the number.

Embodiment 1

In this embodiment, a composite device of one embodiment of the presentinvention and a performance method of the composite device is described.

Note that in the drawings attached to this specification, the blockdiagram in which components are classified according to their functionsand shown as independent blocks is illustrated; however, it is difficultto separate actual components completely according to their functions,and one component may be related to a plurality of functions or aplurality of components may achieve one function.

The composite device of one embodiment of the present invention has afunction of obtaining a fingerprint of a finger touching an input meanssuch as a screen (also referred to as a touch panel) or a touch pad andexecuting user authentication processing using the fingerprint. Everytime a user touches the screen or touch pad to operate the device, theauthentication processing can be executed; thus, a device with anextremely high security level can be achieved.

Meanwhile, in the case of a device using only an authentication methodusing a password or the like, for example, there is a risk ofunauthorized use of the device by a malicious user obtaining thepassword improperly. Furthermore, even in the case of using onlybiometric authentication such as fingerprint authentication or faceauthentication, there is a problem in that the device can be unlockedwhile an authentic user is unaware, for example, sleeping.

In the composite device of one embodiment of the present invention,authentication processing is executed every time the composite device isoperated using a screen or touch pad; thus, even in the case whereunlocking the device or logging in to various systems is performed by anunauthorized method, the device can immediately turn into a locked stateto prevent a malicious user from using the device.

A more specific structure example of the composite device of oneembodiment of the present invention is described below with reference todrawings.

[Structure Example of Composite Device]

FIG. 1 illustrates a block diagram of a device 10 of one embodiment ofthe present invention. The device 10 includes a control portion 11, adisplay portion 12, an authentication portion 13, and a memory portion14. The display portion 12 includes a detection portion 21.

The device 10 can be used as an electronic device such as an informationterminal device, for example.

The authentication portion 13 has a function of executing userauthentication processing. The authentication portion 13 can execute theuser authentication processing and then output the result to the controlportion 11.

Examples of authentication methods that can be applied to theauthentication portion 13 include authentication methods employing userinput such as password entry or pattern entry, authentication methodsemploying user's biological information (also referred to as biometricauthentication) such as fingerprint authentication, vein authentication,voiceprint authentication, face authentication, and iris authentication,and the like.

The display portion 12 has a function of displaying an image, a functionof detecting a touch, and a function of obtaining fingerprint data of afinger touching a screen or the like. Here, an example where the displayportion 12 includes the detection portion 21 is illustrated. Thedetection portion 21 is a portion having, out of the above functions ofthe display portion 12, the function of detecting a touch and thefunction of obtaining fingerprint data. The display portion 12 can alsobe referred to as a touch panel with a fingerprint data obtainingfunction.

The detection portion 21 has a function of outputting the positioninformation of a finger touching a screen to the control portion 11.Furthermore, the detection portion 21 has a function of capturing afingerprint image of a finger touching the screen and outputting theimage data as fingerprint data to the control portion 11.

It is preferable that the display portion 12 be capable of obtainingfingerprint data of a finger touching any position on the screen. Inother words, a range where the touch sensor functions and a range wherefingerprint data can be obtained preferably match or substantially matchon the screen.

The memory portion 14 has a function of retaining user's fingerprintdata registered in advance. The memory portion 14 can output thefingerprint data to the control portion 11 in accordance with therequest from the control portion 11.

The memory portion 14 preferably retains fingerprint data of all thefingers of a user operating the screen. For example, two kinds offingerprint data of user's right and left index fingers can be retained.In addition to them, it is preferable that one or more kinds offingerprint data of a middle finger, a ring finger, a little finger, anda thumb be retained.

The control portion 11 has a function of bringing the system from thelocked state into the unlocked state in the case where a user isauthenticated by user authentication executed by the authenticationportion 13.

Furthermore, the control portion 11 has a function of requesting thedetection portion 21 to obtain fingerprint data when a touch is detectedby the detection portion 21. Then, the control portion 11 has a functionof comparing the fingerprint data input from the detection portion 21with the fingerprint data registered in advance. When the controlportion 11 determines that these two kinds of data match, the controlportion 11 executes processing in accordance with touch operation by auser. On the other hand, when the control portion 11 determines that thetwo kinds of data do not match, the control portion 11 brings the systemfrom the unlocked state into the locked state.

Examples of a fingerprint authentication method executed by the controlportion 11 include a method using the degree of similarity between twoimages compared, e.g., a template matching method or a pattern matchingmethod. Alternatively, fingerprint authentication processing may beexecuted by inference using machine learning. At this time, thefingerprint authentication processing is preferably executed byinference using a neural network, in particular.

The control portion 11 can function as, for example, a centralprocessing unit (CPU). The control portion 11 interprets and executesinstructions from various programs with use of a processor to processvarious kinds of data and control programs. Programs that might beexecuted by the processor may be stored in a memory region of theprocessor or may be stored in the memory portion 14.

[Operation Example of Device 10]

An operation example of the device 10 is described below. FIG. 2 is aflow chart of the operation of the device 10. The flow chart shown inFIG. 2 includes Step S0 to Step S9.

First, the operation starts in Step S0. The operation starts whenpower-on of an electronic device incorporating the device 10, a press ofa physical button, a touch on a display portion 12 by a user, a largechange in the attitude of the electronic device, or the like is sensed,for example. At this time, the device 10 is in the locked state (alsoreferred to as a log-out state or log-off state).

In Step S1, authentication data that is necessary for the authenticationprocessing of the authentication portion 13 is obtained.

In Step S2, the authentication portion 13 executes user authenticationprocessing on the basis of the authentication data. When the user isauthenticated, the processing proceeds to Step S3. When the user is notauthenticated, the processing returns to Step S1 while the systemremains in the locked state.

In Step S3, the control portion 11 brings the system into the unlockedstate (also referred to as bringing the system into a log-in state).

In Step S4, the detection portion 21 detects touch operation. When atouch is detected, the processing proceeds to Step S5. When touchoperation is not performed, the system is in standby until touchoperation is performed while remaining in the unlocked state (theprocessing proceeds to Step S4 again).

In the case where touch operation is not performed for a certain periodin Step S4, the control portion 11 may bring the system into the lockedstate. At this time, the processing may proceed to Step S1.

In Step S5, the detection portion 21 obtains fingerprint data. Thedetection portion 21 outputs the obtained fingerprint data to thecontrol portion 11.

In Step S6, the control portion 11 executes fingerprint authenticationprocessing. Specifically, the fingerprint data retained in the memoryportion 14 and the fingerprint data obtained by the detection portion 21are compared and determined whether the data match or not. When the datais authenticated (when the two kinds of fingerprint data are determinedto match), the processing proceeds to Step S7. On the other hand, whenthe data is not authenticated (when the two kinds of fingerprint dataare not determined to match), the processing proceeds to Step S8.

In Step S7, the control portion 11 executes processing on the basis ofthe touch operation detected in Step S4. The examples of touch operationinclude operations such as tap, long tap, swipe, pinch in, pinch out,flick, and drag.

After processing is executed in Step S7, the processing proceeds to StepS4 and the system is in standby until touch operation is performedagain.

In Step S8, the system is brought into the locked state. This rendersthe electronic device unavailable to the user operating the electronicdevice. Alternatively, available functions are limited.

In Step S9, the operation ends. In Step S9, the power may be turned off,the system may be shut down, or the processing may proceed to Step S1again while the system remains in the locked state (or a log-out state).

The above is the description of the flow chart shown in FIG. 2.

Note that a processing method, an operation method, a performancemethod, a display method, or the like that is executed by the compositedevice of one embodiment of the present invention might be described asa program, for example. For example, a program in which the processingmethod, operation method, performance method, display method, or thelike that is described above as an example and executed by the device 10and the like is written can be stored in a non-temporary storage mediumand can be read and executed by an arithmetic device or the likeincluded in the control portion 11 of the device 10. Accordingly, aprogram that makes hardware execute the performance method or the likedescribed above as an example and a non-temporary memory mediumincluding the program are of embodiments of the present invention.

MODIFICATION EXAMPLE

Although the display portion 12 includes the detection portion 21 in theabove example, they may be provided separately. A device 10A illustratedin FIG. 3 is an example in which the detection portion 21 is notincluded in the display portion 12.

Examples of the detection portion 21 of the device 10A include a touchpad that does not have an image display function.

Alternatively, the device 10A may include the following two: the displayportion 12 not having a function of obtaining fingerprint data and thedetection portion 21 having a function of displaying an image. In otherwords, a touch panel with a fingerprint data obtaining function may beused as the detection portion 12 that is an input means, and the displayportion 12 may be separately included as an image display means.

Specific Example

A specific example of an electronic device to which the composite deviceof one embodiment of the present invention is applied is describedbelow.

FIG. 4A schematically illustrates an electronic device 30 and a finger25 operating the electronic device 30. The electronic device 30 includesa display portion 31. The electronic device 30 is a portable informationterminal device functioning as a smartphone, for example.

In FIG. 4A, the fingertip of the finger 25 touches the display portion31. At this time, the display portion 31 can obtain fingerprint data 26of the finger 25.

FIG. 4B illustrates the fingerprint data 26 obtained by the displayportion 31 and fingerprint data 27 of a user registered in advance inthe electronic device 30. In FIG. 4B, it is determined that thefingerprint data 26 and the fingerprint data 27 match. Accordingly,since the user using the electronic device 30 is authenticated, the usercan move an icon image 35 by drag operation as illustrated in FIG. 4A,for example.

FIG. 4C illustrates a state where the electronic device 30 is to beoperated with a finger 25X of a user who is not registered in theelectronic device 30. As illustrated in FIG. 4D, the user is notauthenticated because fingerprint data 26X of the finger 25X and thefingerprint data 27 registered in advance do not match.

In FIG. 4C, the electronic device 30 is in the locked state (or thelog-out state) so as not to be used by the user. Therefore, even whenthe operation to move the icon image 35 with the finger 25X isperformed, the electronic device 30 does not react (the operation is notaccepted). At this time, as illustrated in FIG. 4C, the display portion31 may display information 36 indicating that the electronic device 30is in the locked state.

FIG. 5A illustrates an electronic device 40 to which the compositedevice of one embodiment of the present invention is applied. Theelectronic device 40 functions as a laptop personal computer.

The electronic device 40 includes a display portion 41, an input portion42, a plurality of input keys 43, a housing 44, a housing 45, a hingeportion 46, and the like. The housing 44 is provided with the displayportion 41. The housing 45 is provided with the input portion 42 and theinput keys 43. The housing 44 and the housing 45 are joined together bythe hinge portion 46.

The input portion 42 functions as a touch pad. The input portion 42 hasa function of obtaining the information of a position where thefingertip of the finger 25 touches and the fingerprint data of thefingertip.

In the case where a touch panel is used for the display portion 41, thedisplay portion 41 preferably has a function of obtaining fingerprintdata.

FIG. 5B illustrates an electronic device 40A using a flexible displayfor a display portion 41A. The display portion 41A is provided acrossthe housing 44 and the housing 45. Thus, seamless display across twohousings is possible.

The display portion 41A has a function of displaying an image, afunction of obtaining the information of a position where the fingertipof the finger 25 touches, and a function of obtaining the fingerprintdata of the fingertip.

FIG. 5C illustrates an electronic device 40B provided with displayportions on each of the two housings. The housing 44 is provided with adisplay portion 41B. The housing 45 is provided with a display portion41C.

At least one of the display portion 41B and the display portion 41C,preferably both of them, has/have a function of displaying an image, afunction of obtaining the information of a position where the fingertipof the finger 25 touches, and a function of obtaining the fingerprintdata of the fingertip.

The above is the description of the specific example.

At least part of this embodiment can be implemented in combination withthe other embodiments described in this specification as appropriate.

Embodiment 2

In this embodiment, a display device that can be used for the displayportion of the composite device of one embodiment of the presentinvention is described. A display device shown below as an exampleincludes a light-emitting element and a light-receiving element. Thedisplay device has a function of displaying an image, a function ofperforming position detection with reflected light from an object to bedetected, and a function of capturing an image of a fingerprint or thelike with reflected light from an object to be detected. The displaydevice shown below as an example can also be regarded to have a functionof a touch panel and a function of a fingerprint sensor.

A display device according to one embodiment of the present inventionincludes a light-emitting element emitting first light (a light-emittingdevice) and a light-receiving element receiving the first light (alight-receiving device). The light-receiving element is preferably aphotoelectric conversion element. As the first light, visible light orinfrared light can be used. In the case where infrared light is used asthe first light, in addition to the light-emitting element emitting thefirst light, a light-emitting element emitting visible light can beincluded.

In addition, the display device includes a pair of substrates (alsoreferred to as a first substrate and a second substrate). Thelight-emitting element and the light-receiving element are arrangedbetween the first substrate and the second substrate. The firstsubstrate is positioned on a display surface side, and the secondsubstrate is positioned on a side opposite to the display surface side.

Visible light is emitted from the light-emitting element to the outsidethrough the first substrate. A plurality of such light-emitting elementsarranged in a matrix are included in the display device, so that animage can be displayed.

The first light emitted from the light-emitting element reaches asurface of the first substrate. Here, when an object touches the surfaceof the first substrate, the first light is scattered at an interfacebetween the first substrate and the object, and part of the scatteredlight enters the light-receiving element. When receiving the firstlight, the light-receiving element can convert the light into anelectric signal in accordance with the intensity of the first light andoutput the electric signal. A plurality of light-receiving elementsarranged in a matrix are included in the display device, wherebypositional information, shape, or the like of the object touching thefirst substrate can be detected. That is, the display device canfunction as an image sensor panel, a touch sensor panel, or the like.

Note that even in the case where the object does not touch the surfaceof the first substrate, the first light that has passed through thefirst substrate is reflected or scattered in the surface of the object,and the reflected light or the scattered light enters thelight-receiving element through the first substrate. Thus, the displaydevice can also be used as a non-contact touch sensor panel (alsoreferred to as a near-touch panel).

In the case where visible light is used as the first light, the firstlight used for image display can be used as a light source of a touchsensor. In that case, the light-emitting element has a function of adisplay element and a function of a light source, so that the structureof the display device can be simplified. In contrast, in the case whereinfrared light is used as the first light, a user does not perceive theinfrared light, so that image capturing or sensing can be performed bythe light-receiving element without a reduction in visibility of adisplayed image.

In the case where infrared light is used as the first light, infraredlight, preferably near-infrared light is used. In particular,near-infrared light having one or more peaks in the range of awavelength greater than or equal to 700 nm and less than or equal to2500 nm can be favorably used. In particular, the use of light havingone or more peaks in the range of a wavelength greater than or equal to750 nm and less than or equal to 1000 nm is preferable because itpermits an extensive choice of a material used for an active layer ofthe light-receiving element.

When a fingertip touches a surface of the display device, an image ofthe shape of a fingerprint can be captured. A fingerprint has adepression and a projection. When a finger touches a light guide plate,the first light is likely to be scattered by the projection of thefingerprint touching the surface of the first substrate. Therefore, theintensity of scattered light that enters the light-receiving elementoverlapping with the projection of the fingerprint is high, and theintensity of scattered light that enters the light-receiving elementoverlapping with the depression is low. Utilizing this, a fingerprintimage can be captured. A device including the display device of oneembodiment of the present invention can perform fingerprintauthentication, which is a kind of biometric authentication, byutilizing a captured fingerprint image.

In addition, the display device can also capture an image of a bloodvessel, especially a vein of a finger, a hand, or the like. For example,since light having a wavelength of 760 nm and its vicinity is notabsorbed by reduced hemoglobin in a vein, reflected light from a palm, afinger, or the like is received by the light-receiving element andcaptured as an image, so that the position of the vein can be detected.The device including the display device of one embodiment of the presentinvention can perform vein authentication, which is a kind of biometricauthentication, by utilizing a captured vein image.

In addition, the device including the display device of one embodimentof the present invention can also perform touch sensing, fingerprintauthentication, and vein authentication at the same time. Thus,biometric authentication with a high security level can be executed atlow cost without increasing the number of components.

The light-receiving element is preferably an element that can receiveboth infrared light and visible light. In that case, as thelight-emitting element, both a light-emitting element emitting infraredlight and a light-emitting element emitting visible light are preferablyincluded. Accordingly, visible light is reflected by a user's finger andreflected light is received by the light-receiving element, so that animage of a fingerprint can be captured. Furthermore, an image of theshape of a vein can be captured with infrared light. Accordingly, bothfingerprint authentication and vein authentication can be executed inone display device. Moreover, fingerprint image capturing and vein imagecapturing may be executed either at different timings or at the sametime. In the case where fingerprint image capturing and vein imagecapturing are performed at the same time, image data including both dataon the shape of a fingerprint and data on the shape of a vein can beobtained, so that biometric authentication with higher accuracy can beachieved.

The display device of one embodiment of the present invention may have afunction of sensing user's health conditions. For example, by utilizingchanges in reflectance and transmittance with respect to visible lightand infrared light in accordance with a change in blood oxygensaturation, temporal modulation of the oxygen saturation is obtained,from which a heart rate can be measured. Furthermore, a glucoseconcentration in dermis, a neutral fat concentration in the blood, orthe like can also be measured with infrared light or visible light. Thedevice including the display device of one embodiment of the presentinvention can be used as a health care device capable of obtaining indexdata on user's health conditions.

As the first substrate, a sealing substrate for sealing thelight-emitting element, a protective film, or the like can be used. Inaddition, a resin layer may be provided between the first substrate andthe second substrate to attach the first substrate and the secondsubstrate to each other.

Here, as the light-emitting element, an EL element such as an OLED(Organic Light Emitting Diode) or a QLED (Quantum-dot Light EmittingDiode) is preferably used. As a light-emitting substance included in theEL element, a substance which emits fluorescence (a fluorescentmaterial), a substance which emits phosphorescence (a phosphorescentmaterial), an inorganic compound (e.g., a quantum dot material), asubstance which exhibits thermally activated delayed fluorescence (athermally activated delayed fluorescent (TADF) material), and the likecan be given. Alternatively, an LED such as a micro-LED (Light EmittingDiode) can be used as the light-emitting element.

As the light-receiving element, a pn photodiode or a pin photodiode canbe used, for example. The light-receiving element functions as aphotoelectric conversion element that detects light incident on thelight-receiving element and generates charge. The amount of generatedcharge in the photoelectric conversion element is determined dependingon the amount of incident light. It is particularly preferable to use anorganic photodiode including a layer containing an organic compound asthe light-receiving element. An organic photodiode, which is easily madethin, lightweight, and large in area and has a high degree of freedomfor shape and design, can be used in a variety of display devices.

The light-emitting element can have a stacked-layer structure includinga light-emitting layer between a pair of electrodes, for example. Thelight-receiving element can have a stacked-layer structure including anactive layer between a pair of electrodes. A semiconductor material canbe used for the active layer of the light-receiving element. Forexample, an inorganic semiconductor material such as silicon can beused.

An organic compound is preferably used for the active layer of thelight-receiving element. In that case, one electrode of thelight-emitting element and one electrode of the light-receiving element(the electrodes are also referred to as pixel electrodes) are preferablyprovided on the same plane. It is further preferable that the otherelectrode of the light-emitting element and the other electrode of thelight-receiving element be an electrode (also referred to as a commonelectrode) formed using one continuous conductive layer. It is stillfurther preferable that the light-emitting element and thelight-receiving element include a common layer. Thus, the manufacturingprocess of the light-emitting element and the light-receiving elementcan be simplified, so that the manufacturing cost can be reduced and themanufacturing yield can be increased.

More specific examples are described below with reference to drawings.

Structure Example 1 of Display Panel Structure Example 1-1

A schematic view of a display panel 50 is illustrated in FIG. 6A. Thedisplay panel 50 includes a substrate 51, a substrate 52, alight-receiving element 53, a light-emitting element 57R, alight-emitting element 57G, a light-emitting element 57B, a functionallayer 55, and the like.

The light-emitting element 57R, the light-emitting element 57G, thelight-emitting element 57B, and the light-receiving element 53 areprovided between the substrate 51 and the substrate 52.

The light-emitting element 57R, the light-emitting element 57G, and thelight-emitting element 57B emit red (R) light, green (G) light, and blue(B) light, respectively.

The display panel 50 includes a plurality of pixels arranged in amatrix. One pixel includes one or more subpixels. One subpixel includesone light-emitting element. For example, the pixel can have a structureincluding three subpixels (e.g., three colors of R, G, and B or threecolors of yellow (Y), cyan (C), and magenta (M)) or four subpixels(e.g., four colors of R, G, B, and white (W) or four colors of R, G, B,and Y). The pixel further includes the light-receiving element 53. Thelight-receiving element 53 may be provided in all the pixels or may beprovided in some of the pixels. In addition, one pixel may include aplurality of light-receiving elements 53.

FIG. 6A illustrates a state where a finger 60 touches a surface of thesubstrate 52. Part of light emitted from the light-emitting element 57Gis reflected or scattered by a contact portion of the substrate 52 andthe finger 60. Then, part of the reflected light or scattered lightenters the light-receiving element 53, and the contact of the finger 60with the substrate 52 can be detected. That is, the display panel 50 canfunction as a touch panel.

The functional layer 55 includes a circuit that drives thelight-emitting element 57R, the light-emitting element 57G, and thelight-emitting element 57B and a circuit that drives the light-receivingelement 53. The functional layer 55 is provided with a switch, atransistor, a capacitor, a wiring, and the like. Note that in the casewhere the light-emitting element 57R, the light-emitting element 57G,the light-emitting element 57B, and the light-receiving element 53 aredriven by a passive-matrix method, a structure not provided with aswitch or a transistor may be employed.

The display panel 50 may have a function of detecting a fingerprint ofthe finger 60. FIG. 6B schematically illustrates an enlarged view of thecontact portion in a state where the finger 60 touches the substrate 52.FIG. 6B illustrates light-emitting elements 57 and the light-receivingelements 53 that are alternately arranged.

The fingerprint of the finger 60 is formed of depressions andprojections. Therefore, as illustrated in FIG. 6B, the projections ofthe fingerprint touch the substrate 52, and scattered light (indicatedby dashed arrows) occurs at the contact surfaces.

As illustrated in FIG. 6B, in the intensity distribution of thescattered light on the surface of the substrate 52 in contact with thefinger 60, the intensity of light almost perpendicular to the contactsurface is the highest, and the intensity of light becomes lower as anangle becomes larger in an oblique direction. Thus, the intensity oflight received by the light-receiving element 53 positioned directlybelow the contact surface (i.e., overlapping with the contact surface)is the highest. Of the scattered light, light at greater than or equalto a predetermined scattering angle is fully reflected at the othersurface (a surface opposite to the contact surface) of the substrate 52and does not reach the light-receiving element 53 side. As a result, aclear fingerprint image can be captured.

In the case where an arrangement interval between the light-receivingelements 53 is smaller than a distance between two projections of afingerprint, preferably a distance between a depression and a projectionadjacent to each other, a clear fingerprint image can be obtained. Thedistance between a depression and a projection of a human's fingerprintis approximately 200 μm; thus, the arrangement interval between thelight-receiving elements 53 is, for example, less than or equal to 400μm, preferably less than or equal to 200 μm, further preferably lessthan or equal to 150 μm, still further preferably less than or equal to100 μm, even still further preferably less than or equal to 50 μm andgreater than or equal to 1 μm, preferably greater than or equal to 10μm, further preferably greater than or equal to 20 μm.

FIG. 6C illustrates an example of a fingerprint image captured with thedisplay panel 50. In an image-capturing range 63 in FIG. 6C, the outlineof the finger 60 is indicated by a dashed line and the outline of acontact portion 61 is indicated by a dashed-dotted line. In the contactportion 61, a high-contrast image of a fingerprint 62 can be capturedowing to a difference in the amount of light incident on thelight-receiving elements 53.

The display panel 50 can also function as a touch panel or a pen tablet.FIG. 6D illustrates a state where a tip of a stylus 65 slides in adirection indicated by a dashed arrow while the tip of the stylus 65touches the substrate 52.

As illustrated in FIG. 6D, when light scattered by the contact surfaceof the tip of the stylus 65 and the substrate 52 enters thelight-receiving element 53 that overlaps with the contact surface, theposition of the tip of the stylus 65 can be detected with high accuracy.

FIG. 6E illustrates an example of a path 66 of the stylus 65 that isdetected by the display panel 50. The display panel 50 can detect theposition of an object to be detected, such as the stylus 65, with highposition accuracy, so that high-definition drawing can be performedusing a drawing application or the like. Unlike the case of using acapacitive touch sensor, an electromagnetic induction touch pen, or thelike, the position detection can be performed even when the stylus 65 isan object with high insulating properties; thus, the material of a tipportion of the stylus 65 is not limited, and a variety of writingmaterials (e.g., a brush, a glass pen, a quill pen, and the like) can beused.

Here, FIG. 6F to FIG. 6H illustrate examples of a pixel that can be usedin the display panel 50.

Pixels illustrated in FIG. 6F and FIG. 6G include the light-emittingelement 57R for red (R), the light-emitting element 57G for green (G),the light-emitting element 57B for blue (B), and the light-receivingelement 53. The pixels each include a pixel circuit for driving thelight-emitting element 57R, the light-emitting element 57G, thelight-emitting element 57B, and the light-receiving element 53.

FIG. 6F illustrates an example in which three light-emitting elementsand one light-receiving element are provided in a matrix of 2×2. FIG. 6Gillustrates an example in which three light-emitting elements arearranged in one line and one laterally long light-receiving element 53is provided below the three light-emitting elements.

The pixel illustrated in FIG. 6H is an example including alight-emitting element 57W for white (W). Here, four light-emittingelements are arranged in one line and the light-receiving element 53 isprovided below the four light-emitting elements.

Note that the pixel structure is not limited to the above structure, anda variety of arrangement methods can be employed.

Structure Example 1-2

An example of a structure including a light-emitting element emittingvisible light, a light-emitting element emitting infrared light, and alight-receiving element is described below.

A display panel 50A illustrated in FIG. 7A includes a light-emittingelement 57IR in addition to the components illustrated in FIG. 6A as anexample. The light-emitting element 57IR is a light-emitting elementemitting infrared light IR. Moreover, in that case, an element capableof receiving at least the infrared light IR emitted from thelight-emitting element 57IR is preferably used as the light-receivingelement 53. As the light-receiving element 53, an element capable ofreceiving both visible light and infrared light is further preferablyused.

As illustrated in FIG. 7A, when the finger 60 touches the substrate 52,the infrared light IR emitted from the light-emitting element 57IR isreflected or scattered by the finger 60 and part of reflected light orscattered light enters the light-receiving element 53, so that thepositional information of the finger 60 can be obtained.

FIG. 7B to FIG. 7D illustrate examples of a pixel that can be used inthe display panel 50A.

FIG. 7B illustrates an example in which three light-emitting elementsare arranged in one line and the light-emitting element 57IR and thelight-receiving element 53 are arranged below the three light-emittingelements in a horizontal direction. FIG. 6C illustrates an example inwhich four light-emitting elements including the light-emitting element57IR are arranged in one line and the light-receiving element 53 isprovided below the four light-emitting elements.

FIG. 7C illustrates an example in which three light-emitting elementsand the light-receiving element 53 arranged in all directions with thelight-emitting element 57IR used as a center.

Note that in the pixels illustrated in FIG. 7B to FIG. 7D, thelight-emitting elements can be interchanged with each other, or thelight-emitting element and the light-receiving element can beinterchanged with each other.

The above is the description of Structure example 2.

Structure Example 2 of Display Panel Structure Example 2-1

FIG. 8A is a schematic cross-sectional view of a display panel 100A.

The display panel 100A includes a light-receiving element 110 and alight-emitting element 190. The light-receiving element 110 includes apixel electrode 111, a common layer 112, an active layer 113, a commonlayer 114, and a common electrode 115. The light-emitting element 190includes a pixel electrode 191, the common layer 112, a light-emittinglayer 193, the common layer 114, and the common electrode 115.

The pixel electrode 111, the pixel electrode 191, the common layer 112,the active layer 113, the light-emitting layer 193, the common layer114, and the common electrode 115 may each have a single-layer structureor a stacked-layer structure.

The pixel electrode 111 and the pixel electrode 191 are positioned overan insulating layer 214. The pixel electrode 111 and the pixel electrode191 can be formed using the same material in the same step.

The common layer 112 is positioned over the pixel electrode 111 and thepixel electrode 191. The common layer 112 is a layer shared by thelight-receiving element 110 and the light-emitting element 190.

The active layer 113 overlaps with the pixel electrode 111 with thecommon layer 112 therebetween. The light-emitting layer 193 overlapswith the pixel electrode 191 with the common layer 112 therebetween. Theactive layer 113 includes a first organic compound, and thelight-emitting layer 193 includes a second organic compound that isdifferent from the first organic compound.

The common layer 114 is positioned over the common layer 112, the activelayer 113, and the light-emitting layer 193. The common layer 114 is alayer shared by the light-receiving element 110 and the light-emittingelement 190.

The common electrode 115 includes a portion overlapping with the pixelelectrode 111 with the common layer 112, the active layer 113, and thecommon layer 114 therebetween. The common electrode 115 further includesa portion overlapping with the pixel electrode 191 with the common layer112, the light-emitting layer 193, and the common layer 114therebetween. The common electrode 115 is a layer shared by thelight-receiving element 110 and the light-emitting element 190.

In the display panel of this embodiment, an organic compound is used forthe active layer 113 of the light-receiving element 110. In thelight-receiving element 110, the layers other than the active layer 113can have structures in common with the layers in the light-emittingelement 190 (EL element). Therefore, the light-receiving element 110 canbe formed concurrently with the formation of the light-emitting element190 only by adding a step of depositing the active layer 113 in themanufacturing process of the light-emitting element 190. Thelight-emitting element 190 and the light-receiving element 110 can beformed over one substrate. Accordingly, the light-receiving element 110can be incorporated into the display panel without a significantincrease in the number of manufacturing steps.

The display panel 100A illustrates an example in which thelight-receiving element 110 and the light-emitting element 190 have acommon structure except that the active layer 113 of the light-receivingelement 110 and the light-emitting layer 193 of the light-emittingelement 190 are separately formed. Note that the structures of thelight-receiving element 110 and the light-emitting element 190 are notlimited thereto. The light-receiving element 110 and the light-emittingelement 190 may include separately formed layers other than the activelayer 113 and the light-emitting layer 193 (see display panels 100D,100E, and 100F described later). The light-receiving element 110 and thelight-emitting element 190 preferably include at least one layer used incommon (common layer). Thus, the light-receiving element 110 can beincorporated into the display panel without a significant increase inthe number of manufacturing steps.

The display panel 100A includes the light-receiving element 110, thelight-emitting element 190, a transistor 131, a transistor 132, and thelike between a pair of substrates (a substrate 151 and a substrate 152).

In the light-receiving element 110, the common layer 112, the activelayer 113, and the common layer 114, which are positioned between thepixel electrode 111 and the common electrode 115, can each also bereferred to as an organic layer (a layer including an organic compound).The pixel electrode 111 preferably has a function of reflecting visiblelight. An end portion of the pixel electrode 111 is covered with a bank216. The common electrode 115 has a function of transmitting visiblelight.

The light-receiving element 110 has a function of detecting light.Specifically, the light-receiving element 110 is a photoelectricconversion element that receives light 122 entering from the outsidethrough the substrate 152 and converts the light 122 into an electricalsignal.

A light-blocking layer BM is provided on a surface of the substrate 152that faces the substrate 151. The light-blocking layer BM has an openingin a position overlapping with the light-receiving element 110 and in aposition overlapping with the light-emitting element 190. Providing thelight-blocking layer BM can control the range where the light-receivingelement 110 detects light.

For the light-blocking layer BM, a material that blocks light emittedfrom the light-emitting element can be used. The light-blocking layer BMpreferably absorbs visible light. As the light-blocking layer BM, ablack matrix can be formed using a metal material or a resin materialcontaining pigment (e.g., carbon black) or dye, for example. Thelight-blocking layer BM may have a stacked-layer structure of a redcolor filter, a green color filter, and a blue color filter.

Here, part of light emitted from the light-emitting element 190 isreflected in the display panel 100A and enters the light-receivingelement 110 in some cases. The light-blocking layer BM can reduce theinfluence of such stray light. For example, in the case where thelight-blocking layer BM is not provided, light 123 a emitted from thelight-emitting element 190 is reflected by the substrate 152 andreflected light 123 b enters the light-receiving element 110 in somecases. Providing the light-blocking layer BM can inhibit the reflectedlight 123 b from entering the light-receiving element 110. Consequently,noise can be reduced, and the sensitivity of a sensor using thelight-receiving element 110 can be increased.

In the light-emitting element 190, the common layer 112, thelight-emitting layer 193, and the common layer 114, which are positionedbetween the pixel electrode 191 and the common electrode 115, can eachalso be referred to as an EL layer. The pixel electrode 191 preferablyhas a function of reflecting visible light. An end portion of the pixelelectrode 191 is covered with the bank 216. The pixel electrode 111 andthe pixel electrode 191 are electrically insulated from each other bythe bank 216. The common electrode 115 has a function of transmittingvisible light.

The light-emitting element 190 has a function of emitting visible light.Specifically, the light-emitting element 190 is an electroluminescentelement that emits light 121 to the substrate 152 side when voltage isapplied between the pixel electrode 191 and the common electrode 115.

It is preferable that the light-emitting layer 193 be formed not tooverlap with a light-receiving region of the light-receiving element110. This inhibits the light-emitting layer 193 from absorbing the light122, increasing the amount of light with which the light-receivingelement 110 is irradiated.

The pixel electrode 111 is electrically connected to a source or a drainof the transistor 131 through an opening provided in the insulatinglayer 214. The end portion of the pixel electrode 111 is covered withthe bank 216.

The pixel electrode 191 is electrically connected to a source or a drainof the transistor 132 through an opening provided in the insulatinglayer 214. The end portion of the pixel electrode 191 is covered withthe bank 216. The transistor 132 has a function of controlling thedriving of the light-emitting element 190.

The transistor 131 and the transistor 132 are on and in contact with thesame layer (the substrate 151 in FIG. 8A).

At least part of a circuit electrically connected to the light-receivingelement 110 and a circuit electrically connected to the light-emittingelement 190 are preferably formed using the same material in the samestep. Thus, the thickness of the display panel can be reduced and themanufacturing process can be simplified compared to the case where thetwo circuits are separately formed.

The light-receiving element 110 and the light-emitting element 190 arepreferably covered with a protective layer 195. In FIG. 8A, theprotective layer 195 is provided on and in contact with the commonelectrode 115. Providing the protective layer 195 can inhibit entry ofimpurities such as water into the light-receiving element 110 and thelight-emitting element 190, so that the reliability of thelight-receiving element 110 and the light-emitting element 190 can beincreased. The protective layer 195 and the substrate 152 are bonded toeach other with an adhesive layer 142.

Note that as illustrated in FIG. 9A, the protective layer is notnecessarily provided over the light-receiving element 110 and thelight-emitting element 190. In FIG. 9A, the common electrode 115 and thesubstrate 152 are bonded to each other with the adhesive layer 142.

A structure that does not include the light-blocking layer BM asillustrated in FIG. 9B may be employed. This can increase thelight-receiving area of the light-receiving element 110, furtherincreasing the sensitivity of the sensor.

Structure Example 2-2

FIG. 8B illustrates a cross-sectional view of a display panel 100B. Notethat in the description of the display panel below, components similarto those of the above-mentioned display panel are not described in somecases.

The display panel 100B illustrated in FIG. 8B includes a lens 149 inaddition to the components of the display panel 100A.

The lens 149 is provided in a position overlapping with thelight-receiving element 110. In the display panel 100B, the lens 149 isprovided in contact with the substrate 152. The lens 149 included in thedisplay panel 100B is a convex lens having a convex surface on thesubstrate 151 side. Note that a convex lens having a convex surface onthe substrate 152 side may be provided in a region overlapping with thelight-receiving element 110.

In the case where both the light-blocking layer BM and the lens 149 areformed on the same plane of the substrate 152, their formation order isnot limited. FIG. 8B illustrates an example in which the lens 149 isformed first; alternatively, the light-blocking layer BM may be formedfirst. In FIG. 8B, an end portion of the lens 149 is covered with thelight-blocking layer BM.

The display panel 100B has a structure in which the light 122 enters thelight-receiving element 110 through the lens 149. With the lens 149, theamount of the light 122 incident on the light-receiving element 110 canbe increased compared to the case where the lens 149 is not provided.This can increase the sensitivity of the light-receiving element 110.

As a method for forming the lens used in the display panel of thisembodiment, a lens such as a microlens may be formed directly over thesubstrate or the light-receiving element, or a lens array formedseparately, such as a microlens array, may be bonded to the substrate.

Structure Example 2-3

FIG. 8C illustrates a schematic cross-sectional view of a display panel100C. The display panel 100C is different from the display panel 100A inthat the substrate 151, the substrate 152, and the bank 216 are notincluded and a substrate 153, a substrate 154, an adhesive layer 155, aninsulating layer 212, and a bank 217 are included.

The substrate 153 and the insulating layer 212 are bonded to each otherwith the adhesive layer 155. The substrate 154 and the protective layer195 are bonded to each other with the adhesive layer 142.

The display panel 100C has a structure obtained in such a manner thatthe insulating layer 212, the transistor 131, the transistor 132, thelight-receiving element 110, the light-emitting element 190, and thelike are formed over a formation substrate and then transferred onto thesubstrate 153. The substrate 153 and the substrate 154 preferably haveflexibility. Accordingly, the flexibility of the display panel 100C canbe increased. For example, a resin is preferably used for each of thesubstrate 153 and the substrate 154.

For each of the substrate 153 and the substrate 154, a polyester resinsuch as polyethylene terephthalate (PET) or polyethylene naphthalate(PEN), a polyacrylonitrile resin, an acrylic resin, a polyimide resin, apolymethyl methacrylate resin, a polycarbonate (PC) resin, a polyethersulfone (PES) resin, a polyamide resin (e.g., nylon or aramid), apolysiloxane resin, a cycloolefin resin, a polystyrene resin, apolyamide-imide resin, a polyurethane resin, a polyvinyl chloride resin,a polyvinylidene chloride resin, a polypropylene resin, apolytetrafluoroethylene (PTFE) resin, an ABS resin, or cellulosenanofiber can be used, for example. Glass that is thin enough to haveflexibility may be used for one or both of the substrate 153 and thesubstrate 154.

As the substrate included in the display panel of this embodiment, afilm having high optical isotropy may be used. Examples of the filmhaving high optical isotropy include a triacetyl cellulose (TAC, alsoreferred to as cellulose triacetate) film, a cycloolefin polymer (COP)film, a cycloolefin copolymer (COC) film, and an acrylic film.

The bank 217 preferably absorbs light emitted by the light-emittingelement. As the bank 217, a black matrix can be formed using a resinmaterial containing a pigment or dye, for example. Moreover, the bank217 can be formed of a colored insulating layer by using a brown resistmaterial.

In some cases, light 123 c emitted by the light-emitting element 190 isreflected by the substrate 152 and the bank 217 and reflected light 123d enters the light-receiving element 110. In other cases, the light 123c passes through the bank 217 and is reflected by a transistor, awiring, or the like, and thus reflected light enters the light-receivingelement 110. When the bank 217 absorbs the light 123 c, the reflectedlight 123 d can be inhibited from entering the light-receiving element110. Consequently, noise can be reduced, and the sensitivity of a sensorusing the light-receiving element 110 can be increased.

The bank 217 preferably absorbs at least light having a wavelength thatis detected by the light-receiving element 110. For example, in the casewhere the light-receiving element 110 detects red light emitted by thelight-emitting element 190, the bank 217 preferably absorbs at least redlight. For example, when the bank 217 includes a blue color filter, thebank 217 can absorb the red light 123 c and thus the reflected light 123d can be inhibited from entering the light-receiving element 110.

Structure Example 2-4

Although the light-emitting element and the light-receiving elementinclude two common layers in the above examples, one embodiment of thepresent invention is not limited thereto. Examples in which commonlayers have different structures are described below.

FIG. 10A illustrates a schematic cross-sectional view of a display panel100D. The display panel 100D is different from the display panel 100A inthat the common layer 114 is not included and a buffer layer 184 and abuffer layer 194 are included. The buffer layer 184 and the buffer layer194 may each have a single-layer structure or a stacked-layer structure.

In the display panel 100D, the light-receiving element 110 includes thepixel electrode 111, the common layer 112, the active layer 113, thebuffer layer 184, and the common electrode 115. In the display panel100D, the light-emitting element 190 includes the pixel electrode 191,the common layer 112, the light-emitting layer 193, the buffer layer194, and the common electrode 115.

The display panel 100D shows an example in which the buffer layer 184between the common electrode 115 and the active layer 113 and the bufferlayer 194 between the common electrode 115 and the light-emitting layer193 are formed separately. As the buffer layer 184 and the buffer layer194, one or both of an electron-injection layer and anelectron-transport layer can be formed, for example.

FIG. 10B illustrates a schematic cross-sectional view of a display panel100E. The display panel 100E is different from the display panel 100A inthat the common layer 112 is not included and a buffer layer 182 and abuffer layer 192 are included. The buffer layer 182 and the buffer layer192 may each have a single-layer structure or a stacked-layer structure.

In the display panel 100E, the light-receiving element 110 includes thepixel electrode 111, the buffer layer 182, the active layer 113, thecommon layer 114, and the common electrode 115. In the display panel100E, the light-emitting element 190 includes the pixel electrode 191,the buffer layer 192, the light-emitting layer 193, the common layer114, and the common electrode 115.

The display panel 100E shows an example in which the buffer layer 182between the pixel electrode 111 and the active layer 113 and the bufferlayer 192 between the pixel electrode 191 and the light-emitting layer193 are formed separately. As the buffer layer 182 and the buffer layer192, one or both of a hole-injection layer and a hole-transport layercan be formed, for example.

FIG. 10C illustrates a schematic cross-sectional view of a display panel100F. The display panel 100F is different from the display panel 100A inthat the common layer 112 and the common layer 114 are not included andthe buffer layer 182, the buffer layer 184, the buffer layer 192, andthe buffer layer 194 are included.

In the display panel 100F, the light-receiving element 110 includes thepixel electrode 111, the buffer layer 182, the active layer 113, thebuffer layer 184, and the common electrode 115. In the display panel100F, the light-emitting element 190 includes the pixel electrode 191,the buffer layer 192, the light-emitting layer 193, the buffer layer194, and the common electrode 115.

In the formation of the light-receiving element 110 and thelight-emitting element 190, not only the active layer 113 and thelight-emitting layer 193 but also other layers can be formed separately.

The display panel 100F shows an example in which the light-receivingelement 110 and the light-emitting element 190 do not have a commonlayer between the pair of electrodes (the pixel electrode 111 or thepixel electrode 191 and the common electrode 115). The light-receivingelement 110 and the light-emitting element 190 included in the displaypanel 100F can be formed in the following manner: the pixel electrode111 and the pixel electrode 191 are formed over the insulating layer 214using the same material in the same step; the buffer layer 182, theactive layer 113, and the buffer layer 184 are formed over the pixelelectrode 111, and the buffer layer 192, the light-emitting layer 193,and the buffer layer 194 are formed over the pixel electrode 191; andthen, the common electrode 115 is formed to cover the buffer layer 184,the buffer layer 194, and the like.

Note that the formation order of the stacked-layer structure of thebuffer layer 182, the active layer 113, and the buffer layer 184 and thestacked-layer structure of the buffer layer 192, the light-emittinglayer 193, and the buffer layer 194 is not particularly limited. Forexample, after the buffer layer 182, the active layer 113, and thebuffer layer 184 are deposited, the buffer layer 192, the light-emittinglayer 193, and the buffer layer 194 may be deposited. In contrast, thebuffer layer 192, the light-emitting layer 193, and the buffer layer 194may be deposited before the buffer layer 182, the active layer 113, andthe buffer layer 184 are deposited. Alternate deposition of the bufferlayer 182, the buffer layer 192, the active layer 113, thelight-emitting layer 193, and the like in this order is also possible.

Structure Example 3 of Display Panel

More specific structure examples of the display panel are describedbelow.

Structure Example 3-1

FIG. 11 illustrates a perspective view of a display panel 200A.

The display panel 200A has a structure in which the substrate 151 andthe substrate 152 are bonded to each other. In FIG. 11, the substrate152 is indicated by a dashed line.

The display panel 200A includes a display portion 162, a circuit 164, awiring 165, and the like. FIG. 11 illustrates an example in which an IC(integrated circuit) 173 and an FPC 172 are mounted on the display panel200A. Thus, the structure illustrated in FIG. 11 can be regarded as adisplay module including the display panel 200A, the IC, and the FPC.

As the circuit 164, a scan line driver circuit can be used.

The wiring 165 has a function of supplying a signal and power to thedisplay portion 162 and the circuit 164. The signal and power are inputto the wiring 165 from the outside through the FPC 172 or from the IC173.

FIG. 11 illustrates an example in which the IC 173 is provided over thesubstrate 151 by a COG (Chip On Glass) method, a COF (Chip On Film)method, or the like. An IC including a scan line driver circuit, asignal line driver circuit, or the like can be used as the IC 173, forexample. Note that the display panel 200A and the display module mayhave a structure that does not include an IC. The IC may be mounted onthe FPC by a COF method or the like.

FIG. 12 illustrates an example of a cross section of part of a regionincluding the FPC 172, part of a region including the circuit 164, partof a region including the display portion 162, and part of a regionincluding an end portion of the display panel 200A illustrated in FIG.11.

The display panel 200A illustrated in FIG. 12 includes a transistor 201,a transistor 205, a transistor 206, the light-emitting element 190, thelight-receiving element 110, and the like between the substrate 151 andthe substrate 152.

The substrate 152 and the insulating layer 214 are attached to eachother with the adhesive layer 142. A solid sealing structure, a hollowsealing structure, or the like can be employed to seal thelight-emitting element 190 and the light-receiving element 110. In FIG.12, a space 143 surrounded by the substrate 152, the adhesive layer 142,and the insulating layer 214 is filled with an inert gas (e.g., nitrogenor argon), that is, a hollow sealing structure is employed. The adhesivelayer 142 may be provided to overlap with the light-emitting element190. The space 143 surrounded by the substrate 152, the adhesive layer142, and the insulating layer 214 may be filled with a resin differentfrom that of the adhesive layer 142.

The light-emitting element 190 has a stacked-layer structure in whichthe pixel electrode 191, the common layer 112, the light-emitting layer193, the common layer 114, and the common electrode 115 are stacked inthis order from the insulating layer 214 side. The pixel electrode 191is connected to a conductive layer 222 b included in the transistor 206through an opening provided in the insulating layer 214. The transistor206 has a function of controlling the driving of the light-emittingelement 190. An end portion of the pixel electrode 191 is covered withthe bank 216. The pixel electrode 191 includes a material that reflectsvisible light, and the common electrode 115 includes a material thattransmits visible light.

The light-receiving element 110 has a stacked-layer structure in whichthe pixel electrode 111, the common layer 112, the active layer 113, thecommon layer 114, and the common electrode 115 are stacked in this orderfrom the insulating layer 214 side. The pixel electrode 111 iselectrically connected to the conductive layer 222 b included in thetransistor 205 through an opening provided in the insulating layer 214.An end portion of the pixel electrode 111 is covered with the bank 216.The pixel electrode 111 includes a material that reflects visible light,and the common electrode 115 includes a material that transmits visiblelight.

Light emitted from the light-emitting element 190 is emitted toward thesubstrate 152 side. Light enters the light-receiving element 110 throughthe substrate 152 and the space 143. For the substrate 152, a materialthat has high transmittance with respect to visible light is preferablyused.

The pixel electrode 111 and the pixel electrode 191 can be formed usingthe same material in the same step. The common layer 112, the commonlayer 114, and the common electrode 115 are used in both thelight-receiving element 110 and the light-emitting element 190. Thelight-receiving element 110 and the light-emitting element 190 can havecommon components except the active layer 113 and the light-emittinglayer 193. Thus, the light-receiving element 110 can be incorporatedinto the display panel 100A without a significant increase in the numberof manufacturing steps.

The light-blocking layer BM is provided on a surface of the substrate152 that faces the substrate 151. The light-blocking layer BM has anopening in a position overlapping with the light-receiving element 110and in a position overlapping with the light-emitting element 190.Providing the light-blocking layer BM can control the range where thelight-receiving element 110 detects light. Furthermore, with thelight-blocking layer BM, light from the light-emitting element 190 canbe inhibited from directly entering the light-receiving element 110.Hence, a sensor with less noise and high sensitivity can be obtained.

The transistor 201, the transistor 205, and the transistor 206 areformed over the substrate 151. These transistors can be formed using thesame materials in the same steps.

An insulating layer 211, an insulating layer 213, an insulating layer215, and the insulating layer 214 are provided in this order over thesubstrate 151. Parts of the insulating layer 211 function as gateinsulating layers of the transistors. Parts of the insulating layer 213function as gate insulating layers of the transistors. The insulatinglayer 215 is provided to cover the transistors. The insulating layer 214is provided to cover the transistors and has a function of aplanarization layer. Note that there is no limitation on the number ofgate insulating layers and the number of insulating layers covering thetransistors, and each insulating layer may have either a single layer ortwo or more layers.

A material through which impurities such as water and hydrogen do noteasily diffuse is preferably used for at least one of the insulatinglayers that cover the transistors. This allows the insulating layer toserve as a barrier layer. Such a structure can effectively inhibitdiffusion of impurities into the transistors from the outside andincrease the reliability of the display device.

An inorganic insulating film is preferably used as each of theinsulating layer 211, the insulating layer 213, and the insulating layer215. As the inorganic insulating film, for example, a silicon nitridefilm, a silicon oxynitride film, a silicon oxide film, a silicon nitrideoxide film, an aluminum oxide film, an aluminum nitride film, or thelike which is an inorganic insulating film can be used. A hafnium oxidefilm, an yttrium oxide film, a zirconium oxide film, a gallium oxidefilm, a tantalum oxide film, a magnesium oxide film, a lanthanum oxidefilm, a cerium oxide film, a neodymium oxide film, or the like may alsobe used. A stack including two or more of the above insulating films mayalso be used.

Here, an organic insulating film often has a lower barrier property thanan inorganic insulating film. Therefore, the organic insulating filmpreferably has an opening in the vicinity of an end portion of thedisplay panel 200A. This can inhibit diffusion of impurities from theend portion of the display panel 200A through the organic insulatingfilm. Alternatively, in order to prevent the organic insulating filmfrom being exposed at the end portion of the display panel 200A, theorganic insulating film may be formed so that its end portion ispositioned on the inner side compared to the end portion of the displaypanel 200A.

An organic insulating film is suitable for the insulating layer 214functioning as a planarization layer. Examples of materials that can beused for the organic insulating film include an acrylic resin, apolyimide resin, an epoxy resin, a polyamide resin, a polyimide-amideresin, a siloxane resin, a benzocyclobutene-based resin, a phenol resin,and precursors of these resins.

In a region 228 illustrated in FIG. 12, an opening is formed in theinsulating layer 214. This can inhibit diffusion of impurities into thedisplay portion 162 from the outside through the insulating layer 214even when an organic insulating film is used as the insulating layer214. Thus, the reliability of the display panel 200A can be increased.

Each of the transistor 201, the transistor 205, and the transistor 206includes a conductive layer 221 functioning as a gate, the insulatinglayer 211 functioning as the gate insulating layer, a conductive layer222 a and the conductive layer 222 b functioning as a source and adrain, a semiconductor layer 231, the insulating layer 213 functioningas the gate insulating layer, and a conductive layer 223 functioning asa gate. Here, a plurality of layers obtained by processing the sameconductive film are shown with the same hatching pattern. The insulatinglayer 211 is positioned between the conductive layer 221 and thesemiconductor layer 231. The insulating layer 213 is positioned betweenthe conductive layer 223 and the semiconductor layer 231.

There is no particular limitation on the structure of the transistorsincluded in the display panel of this embodiment. For example, a planartransistor, a staggered transistor, or an inverted staggered transistorcan be used. A top-gate or bottom-gate transistor structure may beemployed. Alternatively, gates may be provided above and below asemiconductor layer where a channel is formed.

The structure in which the semiconductor layer where a channel is formedis provided between two gates is used for the transistor 201, thetransistor 205, and the transistor 206. The two gates may be connectedto each other and supplied with the same signal to drive the transistor.Alternatively, a potential for controlling the threshold voltage may besupplied to one of the two gates and a potential for driving may besupplied to the other to control the threshold voltage of thetransistor.

There is no particular limitation on the crystallinity of asemiconductor material used for the transistors, and any of an amorphoussemiconductor, a single crystal semiconductor, and a semiconductorhaving crystallinity other than single crystal (a microcrystallinesemiconductor, a polycrystalline semiconductor, or a semiconductorpartly including crystal regions) may be used. A single crystalsemiconductor or a semiconductor having crystallinity is preferablyused, in which case deterioration of the transistor characteristics canbe inhibited.

A semiconductor layer of a transistor preferably includes a metal oxide(also referred to as an oxide semiconductor). Alternatively, thesemiconductor layer of the transistor may include silicon. Examples ofsilicon include amorphous silicon and crystalline silicon (e.g.,low-temperature polysilicon or single crystal silicon).

The semiconductor layer preferably includes indium, M (Mis one or morekinds selected from gallium, aluminum, silicon, boron, yttrium, tin,copper, vanadium, beryllium, titanium, iron, nickel, germanium,zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum,tungsten, and magnesium), and zinc, for example. Specifically, M ispreferably one or more kinds selected from aluminum, gallium, yttrium,and tin.

It is particularly preferable to use an oxide containing indium (In),gallium (Ga), and zinc (Zn) (also referred to as IGZO) for thesemiconductor layer.

In the case where the semiconductor layer is an In-M-Zn oxide, asputtering target used for depositing the In-M-Zn oxide preferably hasthe atomic ratio of In higher than or equal to the atomic ratio of M.Examples of the atomic ratio of the metal elements in such a sputteringtarget include In:M:Zn=1:1:1, In:M:Zn=1:1:1.2, In:M:Zn=2:1:3,In:M:Zn=3:1:2, In:M:Zn=4:2:3, In:M:Zn=4:2:4.1, In:M:Zn=5:1:3,In:M:Zn=5:1:6, In:M:Zn=5:1:7, In:M:Zn=5:1:8, In:M:Zn=6:1:6, andIn:M:Zn=5:2:5.

A target including a polycrystalline oxide is preferably used as thesputtering target, in which case the semiconductor layer havingcrystallinity is easily formed. Note that the atomic ratio in thedeposited semiconductor layer may vary from the above atomic ratiobetween metal elements in the sputtering target in a range of ±40%. Forexample, in the case where the composition of a sputtering target usedfor the semiconductor layer is In:Ga:Zn=4:2:4.1 [atomic ratio], thecomposition of the semiconductor layer to be deposited is sometimes inthe neighborhood of In:Ga:Zn=4:2:3 [atomic ratio].

Note that when the atomic ratio is described as In:Ga:Zn=4:2:3 or in theneighborhood thereof, the case is included where Ga is greater than orequal to 1 and less than or equal to 3 and Zn is greater than or equalto 2 and less than or equal to 4 with In being 4. When the atomic ratiois described as In:Ga:Zn=5:1:6 or in the neighborhood thereof, the caseis included where Ga is greater than 0.1 and less than or equal to 2 andZn is greater than or equal to 5 and less than or equal to 7 with Inbeing 5. When the atomic ratio is described as In:Ga:Zn=1:1:1 or in theneighborhood thereof, the case is included where Ga is greater than 0.1and less than or equal to 2 and Zn is greater than 0.1 and less than orequal to 2 with In being 1.

The transistor included in the circuit 164 and the transistor includedin the display portion 162 may have the same structure or differentstructures. A plurality of transistors included in the circuit 164 mayhave the same structure or two or more kinds of structures. Similarly, aplurality of transistors included in the display portion 162 may havethe same structure or two or more kinds of structures.

A connection portion 204 is provided in a region of the substrate 151that does not overlap with the substrate 152. In the connection portion204, the wiring 165 is electrically connected to the FPC 172 via aconductive layer 166 and a connection layer 242. On a top surface of theconnection portion 204, the conductive layer 166 obtained by processingthe same conductive film as the pixel electrode 191 is exposed. Thus,the connection portion 204 and the FPC 172 can be electrically connectedto each other through the connection layer 242.

A variety of optical members can be arranged on the outer surface of thesubstrate 152. Examples of the optical members include a polarizingplate, a retardation plate, a light diffusion layer (a diffusion film orthe like), an anti-reflective layer, and a light-condensing film.Furthermore, an antistatic film inhibiting the attachment of dust, awater repellent film suppressing the attachment of stain, a hard coatfilm inhibiting generation of a scratch caused by the use, a shockabsorbing layer, or the like may be provided on the outside of thesubstrate 152.

For each of the substrate 151 and the substrate 152, glass, quartz,ceramic, sapphire, a resin, or the like can be used. When a flexiblematerial is used for the substrate 151 and the substrate 152, theflexibility of the display panel can be increased.

As the adhesive layer, a variety of curable adhesives, e.g., aphotocurable adhesive such as an ultraviolet curable adhesive, areactive curable adhesive, a thermosetting adhesive, and an anaerobicadhesive can be used. Examples of these adhesives include an epoxyresin, an acrylic resin, a silicone resin, a phenol resin, a polyimideresin, an imide resin, a PVC (polyvinyl chloride) resin, a PVB(polyvinyl butyral) resin, and an EVA (ethylene vinyl acetate) resin. Inparticular, a material with low moisture permeability, such as an epoxyresin, is preferred. Alternatively, a two-component resin may be used.An adhesive sheet or the like may be used.

As the connection layer 242, an anisotropic conductive film (ACF), ananisotropic conductive paste (ACP), or the like can be used.

The light-emitting element 190 may be of a top emission type, a bottomemission type, a dual emission type, or the like. A conductive film thattransmits visible light is used as the electrode through which light isextracted. A conductive film that reflects visible light is preferablyused as the electrode through which light is not extracted.

The light-emitting element 190 includes at least the light-emittinglayer 193. The light-emitting element 190 may further include, as alayer other than the light-emitting layer 193, a layer containing asubstance with a high hole-injection property, a substance with a highhole-transport property, a hole-blocking material, a substance with ahigh electron-transport property, a substance with a highelectron-injection property, a substance with a bipolar property (asubstance with a high electron- and hole-transport property), or thelike. For example, the common layer 112 preferably includes one or bothof a hole-injection layer and a hole-transport layer. For example, thecommon layer 114 preferably includes one or both of anelectron-transport layer and an electron-injection layer.

The common layer 112, the light-emitting layer 193, and the common layer114 may use either a low molecular compound or a high molecular compoundand may also contain an inorganic compound. The layers that constitutethe common layer 112, the light-emitting layer 193, and the common layer114 can each be formed by a method such as an evaporation method(including a vacuum evaporation method), a transfer method, a printingmethod, an inkjet method, or a coating method.

The light-emitting layer 193 may contain an inorganic compound such asquantum dots as a light-emitting material.

The active layer 113 of the light-receiving element 110 includes asemiconductor. Examples of the semiconductor include an inorganicsemiconductor such as silicon and an organic semiconductor including anorganic compound. This embodiment shows an example in which an organicsemiconductor is used as the semiconductor included in the active layer.The use of an organic semiconductor is preferable because thelight-emitting layer 193 of the light-emitting element 190 and theactive layer 113 of the light-receiving element 110 can be formed by thesame method (e.g., a vacuum evaporation method) and thus the samemanufacturing apparatus can be used.

Examples of an n-type semiconductor material included in the activelayer 113 include electron-accepting organic semiconductor materialssuch as fullerene (e.g., C₆₀ and C₇₀) and derivatives thereof. As ap-type semiconductor material included in the active layer 113, anelectron-donating organic semiconductor material such as copper(II)phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), or zincphthalocyanine (ZnPc) can be given.

For example, the active layer 113 is preferably formed by co-evaporationof an n-type semiconductor and a p-type semiconductor.

As materials that can be used for a gate, a source, and a drain of atransistor and conductive layers such as a variety of wirings andelectrodes included in a display panel, metals such as aluminum,titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum,silver, tantalum, and tungsten, an alloy containing any of these metalsas its main component, and the like can be given. A film containing anyof these materials can be used in a single layer or as a stacked-layerstructure.

As a light-transmitting conductive material, a conductive oxide such asindium oxide, indium tin oxide, indium zinc oxide, zinc oxide, or zincoxide containing gallium, or graphene can be used. Alternatively, ametal material such as gold, silver, platinum, magnesium, nickel,tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, ortitanium, or an alloy material containing the metal material can beused. Further alternatively, a nitride of the metal material (e.g.,titanium nitride) or the like may be used. Note that in the case ofusing the metal material or the alloy material (or the nitride thereof),the thickness is preferably set small enough to be able to transmitlight. A stacked-layer film of any of the above materials can be used asa conductive layer. For example, a stacked-layer film of indium tinoxide and an alloy of silver and magnesium, or the like is preferablyused for increased conductivity. These materials can also be used forconductive layers such as a variety of wirings and electrodes thatconstitute a display panel, and conductive layers (conductive layersfunctioning as a pixel electrode or a common electrode) included in adisplay element.

As an insulating material that can be used for each insulating layer,for example, a resin such as an acrylic resin or an epoxy resin, and aninorganic insulating material such as silicon oxide, silicon oxynitride,silicon nitride oxide, silicon nitride, or aluminum oxide can be given.

Structure Example 3-2

FIG. 13A illustrates a cross-sectional view of a display panel 200B. Thedisplay panel 200B is different from the display panel 200A mainly inthat the lens 149 and the protective layer 195 are included.

Providing the protective layer 195 covering the light-receiving element110 and the light-emitting element 190 can inhibit diffusion ofimpurities such as water into the light-receiving element 110 and thelight-emitting element 190, so that the reliability of thelight-receiving element 110 and the light-emitting element 190 can beincreased.

In the region 228 in the vicinity of an end portion of the display panel200B, the insulating layer 215 and the protective layer 195 arepreferably in contact with each other through an opening in theinsulating layer 214. In particular, the inorganic insulating filmincluded in the insulating layer 215 and the inorganic insulating filmincluded in the protective layer 195 are preferably in contact with eachother. Thus, diffusion of impurities from the outside into the displayportion 162 through the organic insulating film can be inhibited. Thus,the reliability of the display panel 200B can be increased.

FIG. 13B illustrates an example in which the protective layer 195 has athree-layer structure. In FIG. 13B, the protective layer 195 includes aninorganic insulating layer 195 a over the common electrode 115, anorganic insulating layer 195 b over the inorganic insulating layer 195a, and an inorganic insulating layer 195 c over the organic insulatinglayer 195 b.

An end portion of the inorganic insulating layer 195 a and an endportion of the inorganic insulating layer 195 c extend beyond an endportion of the organic insulating layer 195 b and are in contact witheach other. The inorganic insulating layer 195 a is in contact with theinsulating layer 215 (inorganic insulating layer) through the opening inthe insulating layer 214 (organic insulating layer). Accordingly, thelight-receiving element 110 and the light-emitting element 190 can besurrounded by the insulating layer 215 and the protective layer 195,whereby the reliability of the light-receiving element 110 and thelight-emitting element 190 can be increased.

As described above, the protective layer 195 may have a stacked-layerstructure of an organic insulating film and an inorganic insulatingfilm. In that case, an end portion of the inorganic insulating filmpreferably extends beyond an end portion of the organic insulating film.

The lens 149 is provided on a surface of the substrate 152 that facesthe substrate 151. The lens 149 has a convex surface on the substrate151 side. It is preferable that the light-receiving region of thelight-receiving element 110 overlap with the lens 149 and not overlapwith the light-emitting layer 193. Thus, the sensitivity and accuracy ofa sensor using the light-receiving element 110 can be increased.

The refractive index of the lens 149 with respect to the wavelength oflight received by the light-receiving element 110 is preferably greaterthan or equal to 1.3 and less than or equal to 2.5. The lens 149 can beformed using at least one of an inorganic material and an organicmaterial. For example, a material containing a resin can be used for thelens 149. Moreover, a material containing at least one of an oxide and asulfide can be used for the lens 149.

Specifically, a resin containing chlorine, bromine, or iodine, a resincontaining a heavy metal atom, a resin having an aromatic ring, a resincontaining sulfur, or the like can be used for the lens 149.Alternatively, a material containing a resin and nanoparticles of amaterial having a higher refractive index than the resin can be used forthe lens 149. Titanium oxide, zirconium oxide, or the like can be usedfor the nanoparticles.

In addition, cerium oxide, hafnium oxide, lanthanum oxide, magnesiumoxide, niobium oxide, tantalum oxide, titanium oxide, yttrium oxide,zinc oxide, an oxide containing indium and tin, an oxide containingindium, gallium, and zinc, and the like can be used for the lens 149.Alternatively, zinc sulfide or the like can be used for the lens 149.

In the display panel 200B, the protective layer 195 and the substrate152 are bonded to each other with the adhesive layer 142. The adhesivelayer 142 is provided to overlap with the light-receiving element 110and the light-emitting element 190; that is, the display panel 200Bemploys a solid sealing structure.

Structure Example 3-3

FIG. 14A illustrates a cross-sectional view of a display panel 200C. Thedisplay panel 200C is different from the display panel 200B mainly inthe structure of the transistors and including neither thelight-blocking layer BM nor the lens 149.

The display panel 200C includes a transistor 208, a transistor 209, anda transistor 210 over the substrate 151.

Each of the transistor 208, the transistor 209, and the transistor 210includes the conductive layer 221 functioning as a gate, the insulatinglayer 211 functioning as a gate insulating layer, a semiconductor layerincluding a channel formation region 231 i and a pair of low-resistanceregions 231 n, the conductive layer 222 a connected to one of the pairof low-resistance regions 231 n, the conductive layer 222 b connected tothe other of the pair of low-resistance regions 231 n, an insulatinglayer 225 functioning as a gate insulating layer, the conductive layer223 functioning as a gate, and the insulating layer 215 covering theconductive layer 223. The insulating layer 211 is positioned between theconductive layer 221 and the channel formation region 231 i. Theinsulating layer 225 is positioned between the conductive layer 223 andthe channel formation region 231 i.

The conductive layer 222 a and the conductive layer 222 b are connectedto the corresponding low-resistance regions 231 n through openingsprovided in the insulating layer 225 and the insulating layer 215. Oneof the conductive layer 222 a and the conductive layer 222 b serves as asource, and the other serves as a drain.

The pixel electrode 191 of the light-emitting element 190 iselectrically connected to one of the pair of low-resistance regions 231n of the transistor 208 through the conductive layer 222 b.

The pixel electrode 111 of the light-receiving element 110 iselectrically connected to the other of the pair of low-resistanceregions 231 n of the transistor 209 through the conductive layer 222 b.

FIG. 14A illustrates an example in which the insulating layer 225 coversa top surface and a side surface of the semiconductor layer. Meanwhile,FIG. 14B illustrates an example in which the insulating layer 225overlaps with the channel formation region 231 i of the semiconductorlayer 231 and does not overlap with the low-resistance regions 231 n ina transistor 202. The structure illustrated in FIG. 14B can be obtainedby processing the insulating layer 225 using the conductive layer 223 asa mask, for example. In FIG. 14B, the insulating layer 215 is providedto cover the insulating layer 225 and the conductive layer 223, and theconductive layer 222 a and the conductive layer 222 b are connected tothe low-resistance regions 231 n through openings in the insulatinglayer 215. Furthermore, an insulating layer 218 covering the transistormay be provided.

Structure Example 3-4

FIG. 15 illustrates a cross-sectional view of a display panel 200D. Thedisplay panel 200D is different from the display panel 200C mainly inthe structure of the substrates.

The display panel 200D does not include the substrate 151 or thesubstrate 152 and includes the substrate 153, the substrate 154, theadhesive layer 155, and the insulating layer 212.

The substrate 153 and the insulating layer 212 are bonded to each otherwith the adhesive layer 155. The substrate 154 and the protective layer195 are bonded to each other with the adhesive layer 142.

The display panel 200D has a structure obtained in such a manner thatthe insulating layer 212, the transistor 208, the transistor 209, thelight-receiving element 110, the light-emitting element 190, and thelike are formed over a formation substrate and then transferred onto thesubstrate 153. The substrate 153 and the substrate 154 preferably haveflexibility. Accordingly, the flexibility of the display panel 200D canbe increased.

The inorganic insulating film that can be used as the insulating layer211, the insulating layer 213, and the insulating layer 215 can be usedas the insulating layer 212. Alternatively, a stacked-layer film of anorganic insulating film and an inorganic insulating film may be used asthe insulating layer 212. In that case, a film on the transistor 209side is preferably an inorganic insulating film.

The above is the description of the structure examples of the displaypanel.

[Metal Oxide]

A metal oxide that can be used for the semiconductor layer is describedbelow.

Note that in this specification and the like, a metal oxide containingnitrogen is also collectively referred to as a metal oxide in somecases. A metal oxide containing nitrogen may be referred to as a metaloxynitride. For example, a metal oxide containing nitrogen, such as zincoxynitride (ZnON), may be used for the semiconductor layer.

Note that in this specification and the like, CAAC (c-axis alignedcrystal) or CAC (Cloud-Aligned Composite) may be stated. CAAC refers toan example of a crystal structure, and CAC refers to an example of afunction or a material composition.

For example, a CAC (Cloud-Aligned Composite)-OS (Oxide Semiconductor)can be used for the semiconductor layer.

A CAC-OS or a CAC-metal oxide has a conducting function in part of thematerial and has an insulating function in another part of the material;as a whole, the CAC-OS or the CAC-metal oxide has a function of asemiconductor. In the case where the CAC-OS or the CAC-metal oxide isused in a semiconductor layer of a transistor, the conducting functionis to allow electrons (or holes) serving as carriers to flow, and theinsulating function is to not allow electrons serving as carriers toflow. By the complementary action of the conducting function and theinsulating function, a switching function (On/Off function) can be givento the CAC-OS or the CAC-metal oxide. In the CAC-OS or the CAC-metaloxide, separation of the functions can maximize each function.

Furthermore, the CAC-OS or the CAC-metal oxide includes conductiveregions and insulating regions. The conductive regions have theabove-described conducting function, and the insulating regions have theabove-described insulating function. Furthermore, in some cases, theconductive regions and the insulating regions in the material areseparated at the nanoparticle level. Furthermore, in some cases, theconductive regions and the insulating regions are unevenly distributedin the material. Furthermore, in some cases, the conductive regions areobserved to be coupled in a cloud-like manner with their boundariesblurred.

Furthermore, in the CAC-OS or the CAC-metal oxide, the conductiveregions and the insulating regions each have a size greater than orequal to 0.5 nm and less than or equal to 10 nm, preferably greater thanor equal to 0.5 nm and less than or equal to 3 nm, and are dispersed inthe material, in some cases.

Furthermore, the CAC-OS or the CAC-metal oxide includes componentshaving different band gaps. For example, the CAC-OS or the CAC-metaloxide includes a component having a wide gap due to the insulatingregion and a component having a narrow gap due to the conductive region.In the case of the structure, when carriers flow, carriers mainly flowin the component having a narrow gap. Furthermore, the component havinga narrow gap complements the component having a wide gap, and carriersalso flow in the component having a wide gap in conjunction with thecomponent having a narrow gap. Therefore, in the case where theabove-described CAC-OS or CAC-metal oxide is used in a channel formationregion of a transistor, high current driving capability in an on stateof the transistor, that is, a high on-state current and highfield-effect mobility can be obtained.

In other words, the CAC-OS or the CAC-metal oxide can also be referredto as a matrix composite or a metal matrix composite.

Oxide semiconductors (metal oxides) are classified into a single crystaloxide semiconductor and a non-single-crystal oxide semiconductor.Examples of a non-single-crystal oxide semiconductor include a CAAC-OS(c-axis aligned crystalline oxide semiconductor), a polycrystallineoxide semiconductor, an nc-OS (nanocrystalline oxide semiconductor), anamorphous-like oxide semiconductor (a-like OS), and an amorphous oxidesemiconductor.

The CAAC-OS has c-axis alignment, a plurality of nanocrystals areconnected in the a-b plane direction, and its crystal structure hasdistortion. Note that the distortion refers to a portion where thedirection of a lattice arrangement changes between a region with aregular lattice arrangement and another region with a regular latticearrangement in a region where the plurality of nanocrystals areconnected.

The nanocrystal is basically a hexagon but is not always a regularhexagon and is a non-regular hexagon in some cases. Furthermore, apentagonal or heptagonal lattice arrangement, for example, is includedin the distortion in some cases. Note that it is difficult to observe aclear crystal grain boundary (also referred to as grain boundary) evenin the vicinity of distortion in the CAAC-OS. That is, formation of acrystal grain boundary is found to be inhibited by the distortion of alattice arrangement. This is because the CAAC-OS can tolerate distortionowing to a low density of arrangement of oxygen atoms in the a-b planedirection, an interatomic bond length changed by substitution of a metalelement, and the like.

The CAAC-OS tends to have a layered crystal structure (also referred toas a layered structure) in which a layer containing indium and oxygen(hereinafter, In layer) and a layer containing an element M, zinc, andoxygen (hereinafter, (M,Zn) layer) are stacked. Note that indium and theelement M can be replaced with each other, and when the element M in the(M,Zn) layer is replaced with indium, the layer can also be referred toas an (In,M,Zn) layer. Furthermore, when indium in the In layer isreplaced with the element M, the layer can be referred to as an (In,M)layer.

The CAAC-OS is a metal oxide with high crystallinity. On the other hand,a clear crystal grain boundary is difficult to observe in the CAAC-OS;thus, it can be said that a reduction in electron mobility due to thecrystal grain boundary is unlikely to occur. Entry of impurities,formation of defects, or the like might decrease the crystallinity of ametal oxide; thus, it can be said that the CAAC-OS is a metal oxide thathas small amounts of impurities and defects (e.g., oxygen vacancies(also referred to as Vo)). Thus, a metal oxide including a CAAC-OS isphysically stable. Therefore, the metal oxide including a CAAC-OS isresistant to heat and has high reliability.

In the nc-OS, a microscopic region (e.g., a region with a size greaterthan or equal to 1 nm and less than or equal to 10 nm, in particular, aregion with a size greater than or equal to 1 nm and less than or equalto 3 nm) has a periodic atomic arrangement. Furthermore, there is noregularity of crystal orientation between different nanocrystals in thenc-OS. Thus, the orientation in the whole film is not observed.Accordingly, the nc-OS cannot be distinguished from an a-like OS or anamorphous oxide semiconductor by some analysis methods.

Note that indium-gallium-zinc oxide (hereinafter, IGZO), which is a kindof metal oxide containing indium, gallium, and zinc, has a stablestructure in some cases by being formed of the above-describednanocrystals. In particular, crystals of IGZO tend not to grow in theair and thus, a stable structure might be obtained when IGZO is formedof smaller crystals (e.g., the above-described nanocrystals) rather thanlarger crystals (here, crystals with a size of several millimeters orseveral centimeters).

An a-like OS is a metal oxide having a structure between those of thenc-OS and an amorphous oxide semiconductor. The a-like OS includes avoid or a low-density region. That is, the a-like OS has lowcrystallinity as compared with the nc-OS and the CAAC-OS.

An oxide semiconductor (metal oxide) can have various structures thatshow different properties. Two or more of the amorphous oxidesemiconductor, the polycrystalline oxide semiconductor, the a-like OS,the nc-OS, and the CAAC-OS may be included in an oxide semiconductor ofone embodiment of the present invention.

A metal oxide film that functions as a semiconductor layer can bedeposited using either or both of an inert gas and an oxygen gas. Notethat there is no particular limitation on the flow rate ratio of oxygen(the partial pressure of oxygen) at the time of depositing the metaloxide film. However, to obtain a transistor having high field-effectmobility, the flow rate ratio of oxygen (the partial pressure of oxygen)at the time of depositing the metal oxide film is preferably higher thanor equal to 0% and lower than or equal to 30%, further preferably higherthan or equal to 5% and lower than or equal to 30%, still furtherpreferably higher than or equal to 7% and lower than or equal to 15%.

The energy gap of the metal oxide is preferably 2 eV or more, furtherpreferably 2.5 eV or more, still further preferably 3 eV or more. Withuse of a metal oxide having such a wide energy gap, the off-statecurrent of the transistor can be reduced.

The substrate temperature during the deposition of the metal oxide filmis preferably lower than or equal to 350° C., further preferably higherthan or equal to room temperature and lower than or equal to 200° C.,still further preferably higher than or equal to room temperature andlower than or equal to 130° C. The substrate temperature during thedeposition of the metal oxide film is preferably room temperaturebecause productivity can be increased.

The metal oxide film can be formed by a sputtering method.Alternatively, a PLD method, a PECVD method, a thermal CVD method, anALD method, or a vacuum evaporation method, for example, may be used.

The above is the description of the metal oxide.

At least part of this embodiment can be implemented in combination withthe other embodiments described in this specification as appropriate.

Embodiment 3

In this embodiment, a display panel that can be used in the system ofone embodiment of the present invention is described with reference toFIG. 16A and FIG. 16B.

A display panel of one embodiment of the present invention includesfirst pixel circuits each including a light-receiving element and secondpixel circuits each including a light-emitting element. The first pixelcircuits and the second pixel circuits are arranged in a matrix.

FIG. 16A illustrates an example of the first pixel circuit including alight-receiving element, and FIG. 16B illustrates an example of thesecond pixel circuit including a light-emitting element.

A pixel circuit PIX1 illustrated in FIG. 16A includes a light-receivingelement PD, a transistor M1, a transistor M2, a transistor M3, atransistor M4, and a capacitor C1. Here, an example in which aphotodiode is used as the light-receiving element PD is illustrated.

A cathode of the light-receiving element PD is electrically connected toa wiring V1, and an anode thereof is electrically connected to one of asource and a drain of the transistor M1. A gate of the transistor M1 iselectrically connected to a wiring TX, and the other of the source andthe drain thereof is electrically connected to one electrode of thecapacitor C1, one of a source and a drain of the transistor M2, and agate of the transistor M3. A gate of the transistor M2 is electricallyconnected to a wiring RES, and the other of the source and the drainthereof is electrically connected to a wiring V2. One of a source and adrain of the transistor M3 is electrically connected to a wiring V3, andthe other of the source and the drain thereof is electrically connectedto one of a source and a drain of the transistor M4. A gate of thetransistor M4 is electrically connected to a wiring SE, and the other ofthe source and the drain thereof is electrically connected to a wiringOUT1.

A constant potential is supplied to the wiring V1, the wiring V2, andthe wiring V3. When the light-receiving element PD is driven with areverse bias, a potential lower than the potential of the wiring V1 issupplied to the wiring V2. The transistor M2 is controlled by a signalsupplied to the wiring RES and has a function of resetting the potentialof a node connected to the gate of the transistor M3 to a potentialsupplied to the wiring V2. The transistor M1 is controlled by a signalsupplied to the wiring TX and has a function of controlling the timingat which the potential of the node changes, in accordance with a currentflowing through the light-receiving element PD. The transistor M3functions as an amplifier transistor for performing output in responseto the potential of the node. The transistor M4 is controlled by asignal supplied to the wiring SE and functions as a selection transistorfor reading an output corresponding to the potential of the node by anexternal circuit connected to the wiring OUT1.

A pixel circuit PIX2 illustrated in FIG. 16B includes a light-emittingelement EL, a transistor M5, a transistor M6, a transistor M7, and acapacitor C2. Here, an example in which a light-emitting diode is usedas the light-emitting element EL is illustrated. In particular, anorganic EL element is preferably used as the light-emitting element EL.

A gate of the transistor M5 is electrically connected to a wiring VG,one of a source and a drain thereof is electrically connected to awiring VS, and the other of the source and the drain thereof iselectrically connected to one electrode of the capacitor C2 and a gateof the transistor M6. One of a source and a drain of the transistor M6is electrically connected to a wiring V4, and the other thereof iselectrically connected to an anode of the light-emitting element EL andone of a source and a drain of the transistor M7. A gate of thetransistor M7 is electrically connected to a wiring MS, and the other ofthe source and the drain thereof is electrically connected to a wiringOUT2. A cathode of the light-emitting element EL is electricallyconnected to a wiring V5.

A constant potential is supplied to the wiring V4 and the wiring V5. Inthe light-emitting element EL, the anode side can have a high potentialand the cathode side can have a lower potential than the anode side. Thetransistor M5 is controlled by a signal supplied to the wiring VG andfunctions as a selection transistor for controlling a selection state ofthe pixel circuit PIX2. The transistor M6 functions as a drivingtransistor that controls a current flowing through the light-emittingelement EL, in accordance with a potential supplied to the gate. Whenthe transistor M5 is in an on state, a potential supplied to the wiringVS is supplied to the gate of the transistor M6, and the emissionluminance of the light-emitting element EL can be controlled inaccordance with the potential. The transistor M7 is controlled by asignal supplied to the wiring MS and has a function of outputting apotential between the transistor M6 and the light-emitting element EL tothe outside through the wiring OUT2.

Note that in the display panel of this embodiment, the light-emittingelement may be made to emit light in a pulsed manner so as to display animage. A reduction in the driving time of the light-emitting element canreduce the power consumption of the display panel and suppress heatgeneration. An organic EL element is particularly preferable because ofits favorable frequency characteristics. The frequency can be higherthan or equal to 1 kHz and lower than or equal to 100 MHz, for example.

Here, a transistor using a metal oxide (an oxide semiconductor) in asemiconductor layer where a channel is formed is preferably used as thetransistor M1, the transistor M2, the transistor M3, and the transistorM4 included in the pixel circuit PIX1 and the transistor M5, thetransistor M6, and the transistor M7 included in the pixel circuit PIX2.

A transistor using a metal oxide having a wider band gap and a lowercarrier density than silicon can achieve an extremely low off-statecurrent. Thus, such a low off-state current enables retention of chargeaccumulated in a capacitor that is connected in series with thetransistor for a long time. Therefore, it is particularly preferable touse a transistor using an oxide semiconductor as the transistor M1, thetransistor M2, and the transistor M5 each of which is connected inseries with the capacitor C1 or the capacitor C2. Moreover, the use oftransistors using an oxide semiconductor as the other transistors canreduce the manufacturing cost.

Alternatively, transistors using silicon as a semiconductor where achannel is formed can be used as the transistor M1 to the transistor M7.In particular, the use of silicon with high crystallinity, such assingle crystal silicon or polycrystalline silicon, is preferable becausehigh field-effect mobility is achieved and higher-speed operation ispossible.

Alternatively, a transistor using an oxide semiconductor may be used asone or more of the transistor M1 to the transistor M7, and transistorsusing silicon may be used as the other transistors.

Although the transistors are illustrated as n-channel transistors inFIG. 16A and FIG. 16B, p-channel transistors can alternatively be used.

The transistors included in the pixel circuit PIX1 and the transistorsincluded in the pixel circuit PIX2 are preferably formed side by sideover the same substrate. It is particularly preferable that thetransistors included in the pixel circuit PIX1 and the transistorsincluded in the pixel circuit PIX2 be periodically arranged in oneregion.

One or more layers including one or both of the transistor and thecapacitor are preferably provided to overlap with the light-receivingelement PD or the light-emitting element EL. Thus, the effective area ofeach pixel circuit can be reduced, and a high-resolution light-receivingportion or display portion can be achieved.

At least part of this embodiment can be implemented in combination withthe other embodiments described in this specification as appropriate.

Embodiment 4

In this embodiment, electronic devices of embodiments of compositedevices of embodiments of the present invention are described withreference to FIG. 17 to FIG. 19.

An electronic device in this embodiment includes the display device ofone embodiment of the present invention. The display device has afunction of detecting light, and thus can perform biometricauthentication on the display portion and detect a touch or a near touchon the display portion. Unauthorized use of the electronic device of oneembodiment of the present invention is difficult, that is, theelectronic device has extremely high security level. Moreover, theelectronic device can have improved functionality and convenience, forexample.

Examples of the electronic devices include a digital camera, a digitalvideo camera, a digital photo frame, a mobile phone, a portable gameconsole, a portable information terminal, and an audio reproducingdevice, in addition to electronic devices with a relatively largescreen, such as a television device, a desktop or laptop personalcomputer, a monitor of a computer or the like, digital signage, and alarge game machine such as a pachinko machine.

The electronic device in this embodiment may include a sensor (a sensorhaving a function of measuring force, displacement, position, speed,acceleration, angular velocity, rotational frequency, distance, light,liquid, magnetism, temperature, a chemical substance, sound, time,hardness, electric field, current, voltage, electric power, radiation,flow rate, humidity, gradient, oscillation, a smell, or infrared rays).

The electronic device in this embodiment can have a variety offunctions. For example, the electronic device can have a function ofdisplaying a variety of data (a still image, a moving image, a textimage, and the like) on the display portion, a touch panel function, afunction of displaying a calendar, date, time, and the like, a functionof executing a variety of software (programs), a wireless communicationfunction, and a function of reading out a program or data stored in arecording medium.

An electronic device 6500 illustrated in FIG. 17A is a portableinformation terminal that can be used as a smartphone.

The electronic device 6500 includes a housing 6501, a display portion6502, a power button 6503, buttons 6504, a speaker 6505, a microphone6506, a camera 6507, a light source 6508, and the like. The displayportion 6502 has a touch panel function.

The display device of one embodiment of the present invention can beused in the display portion 6502.

FIG. 17B is a schematic cross-sectional view including an end portion ofthe housing 6501 on the microphone 6506 side.

A protection member 6510 having a light-transmitting property isprovided on the display surface side of the housing 6501, and a displaypanel 6511, an optical member 6512, a touch sensor panel 6513, a printedcircuit board 6517, a battery 6518, and the like are provided in a spacesurrounded by the housing 6501 and the protection member 6510.

The display panel 6511, the optical member 6512, and the touch sensorpanel 6513 are fixed to the protection member 6510 with an adhesivelayer (not illustrated).

Part of the display panel 6511 is folded back in a region outside thedisplay portion 6502, and an FPC 6515 is connected to the part that isfolded back. An IC 6516 is mounted on the FPC 6515. The FPC 6515 isconnected to a terminal provided on the printed circuit board 6517.

A flexible display of one embodiment of the present invention can beused as the display panel 6511. Thus, an extremely lightweightelectronic device can be achieved. Since the display panel 6511 isextremely thin, the battery 6518 with high capacity can be mounted withthe thickness of the electronic device controlled. An electronic devicewith a narrow frame can be achieved when part of the display panel 6511is folded back so that the portion connected to the FPC 6515 is providedon the rear side of a pixel portion.

FIG. 18A illustrates an example of a television device. In a televisiondevice 7100, a display portion 7000 is incorporated in a housing 7101.Here, a structure in which the housing 7101 is supported by a stand 7103is illustrated.

The display device of one embodiment of the present invention can beused in the display portion 7000.

Operation of the television device 7100 illustrated in FIG. 18A can beperformed with an operation switch provided in the housing 7101 or aseparate remote controller 7111. Alternatively, the display portion 7000may include a touch sensor, and the television device 7100 may beoperated by a touch on the display portion 7000 with a finger or thelike. The remote controller 7111 may be provided with a display portionfor displaying data output from the remote controller 7111. Withoperation keys or a touch panel provided in the remote controller 7111,channels and volume can be operated and videos displayed on the displayportion 7000 can be operated.

Note that the television device 7100 has a structure in which areceiver, a modem, and the like are provided. A general televisionbroadcast can be received with the receiver. When the television deviceis connected to a communication network with or without wires via themodem, one-way (from a transmitter to a receiver) or two-way (between atransmitter and a receiver or between receivers, for example) datacommunication can be performed.

FIG. 18B illustrates an example of a laptop personal computer. A laptoppersonal computer 7200 includes a housing 7211, a keyboard 7212, apointing device 7213, an external connection port 7214, and the like. Inthe housing 7211, the display portion 7000 is incorporated.

The display device of one embodiment of the present invention can beused in the display portion 7000.

FIG. 18C and FIG. 18D illustrate examples of digital signage.

Digital signage 7300 illustrated in FIG. 18C includes a housing 7301,the display portion 7000, a speaker 7303, and the like. Furthermore, thedigital signage can include an LED lamp, operation keys (including apower switch or an operation switch), a connection terminal, a varietyof sensors, a microphone, and the like.

FIG. 18D is digital signage 7400 attached to a cylindrical pillar 7401.The digital signage 7400 includes the display portion 7000 providedalong a curved surface of the pillar 7401.

The display device of one embodiment of the present invention can beused for the display portion 7000 in FIG. 18C and FIG. 18 and (D).

A larger area of the display portion 7000 can increase the amount ofdata that can be provided at a time. The larger display portion 7000attracts more attention, so that the advertising effectiveness can beenhanced, for example.

The use of a touch panel in the display portion 7000 is preferablebecause in addition to display of an image or a moving image on thedisplay portion 7000, intuitive operation by a user is possible.Moreover, for an application for providing information such as routeinformation or traffic information, usability can be enhanced byintuitive operation.

As illustrated in FIG. 18C and FIG. 18D, the digital signage 7300 or thedigital signage 7400 is preferably capable of working with aninformation terminal 7311 or an information terminal 7411 such as auser's smartphone through wireless communication. For example,information of an advertisement displayed on the display portion 7000can be displayed on a screen of the information terminal 7311 or theinformation terminal 7411. By operation of the information terminal 7311or the information terminal 7411, display on the display portion 7000can be switched.

It is possible to make the digital signage 7300 or the digital signage7400 execute a game with use of the screen of the information terminal7311 or the information terminal 7411 as an operation means(controller). Thus, an unspecified number of users can join in and enjoythe game concurrently.

Electronic devices illustrated in FIG. 19A to FIG. 19F include a housing9000, a display portion 9001, a speaker 9003, an operation key 9005(including a power switch or an operation switch), a connection terminal9006, a sensor 9007 (a sensor having a function of measuring force,displacement, position, speed, acceleration, angular velocity,rotational frequency, distance, light, liquid, magnetism, temperature, achemical substance, sound, time, hardness, electric field, current,voltage, electric power, radiation, flow rate, humidity, gradient,oscillation, a smell, or infrared rays), a microphone 9008, and thelike.

The electronic devices illustrated in FIG. 19A to FIG. 19F have avariety of functions. For example, the electronic devices can have afunction of displaying a variety of information (a still image, a movingimage, a text image, and the like) on the display portion, a touch panelfunction, a function of displaying a calendar, date, time, and the like,a function of controlling processing with use of a variety of software(programs), a wireless communication function, and a function of readingout and processing a program or data stored in a recording medium. Notethat the functions of the electronic devices are not limited thereto,and the electronic devices can have a variety of functions. Theelectronic devices may include a plurality of display portions. Theelectronic devices may each include a camera or the like and have afunction of taking a still image or a moving image and storing the takenimage in a recording medium (an external recording medium or a recordingmedium incorporated in the camera), a function of displaying the takenimage on the display portion, or the like.

The details of the electronic devices illustrated in FIG. 19A to FIG.19F are described below.

FIG. 19A is a perspective view illustrating a portable informationterminal 9101. For example, the portable information terminal 9101 canbe used as a smartphone. Note that the portable information terminal9101 may be provided with the speaker 9003, the connection terminal9006, the sensor 9007, or the like. The portable information terminal9101 can display characters and image information on its plurality ofsurfaces. FIG. 19A illustrates an example where three icons 9050 aredisplayed. Information 9051 indicated by dashed rectangles can bedisplayed on another surface of the display portion 9001. Examples ofthe information 9051 include notification of reception of an e-mail,SNS, or an incoming call, the title and sender of an e-mail, SNS, or thelike, the date, the time, remaining battery, and the reception strengthof an antenna. Alternatively, the icon 9050 or the like may be displayedin the position where the information 9051 is displayed.

FIG. 19B is a perspective view illustrating a portable informationterminal 9102. The portable information terminal 9102 has a function ofdisplaying information on three or more surfaces of the display portion9001. Here, an example in which information 9052, information 9053, andinformation 9054 are displayed on different surfaces is illustrated. Forexample, a user can check the information 9053 displayed in a positionthat can be observed from above the portable information terminal 9102,with the portable information terminal 9102 put in a breast pocket ofhis/her clothes. The user can see the display without taking out theportable information terminal 9102 from the pocket and decide whether toanswer the call, for example.

FIG. 19C is a perspective view illustrating a watch-type portableinformation terminal 9200. The display surface of the display portion9001 is curved and provided, and display can be performed along thecurved display surface. Mutual communication between the portableinformation terminal 9200 and, for example, a headset capable ofwireless communication enables hands-free calling. With the connectionterminal 9006, the portable information terminal 9200 can perform mutualdata transmission with another information terminal and charging. Notethat the charging operation may be performed by wireless power feeding.

FIG. 19D, FIG. 19E, and FIG. 19F are perspective views illustrating afoldable portable information terminal 9201. FIG. 19D is a perspectiveview of an opened state of the portable information terminal 9201, FIG.19F is a perspective view of a folded state thereof, and FIG. 19E is aperspective view of a state in the middle of change from one of FIG. 19Dand FIG. 19F to the other. The portable information terminal 9201 ishighly portable in the folded state and is highly browsable in theopened state because of a seamless large display region. The displayportion 9001 of the portable information terminal 9201 is supported bythree housings 9000 joined by hinges 9055. For example, the displayportion 9001 can be bent with a radius of curvature greater than orequal to 0.1 mm and less than or equal to 150 mm.

At least part of this embodiment can be implemented in combination withthe other embodiments described in this specification as appropriate.

REFERENCE NUMERALS

-   10, 10A: device, 11: control portion, 12: display portion, 13:    authentication portion, 14: memory portion, 21: detection portion,    25, 25X: finger, 26, 26X, 27: fingerprint data, 30: electronic    device, 31: display portion, 35: icon image, 36: information, 40,    40A, 40B: electronic device, 41, 41A, 41B, 41C: display portion, 42:    input portion, 43: input key, 44: housing, 45: housing, 46: hinge    portion

1. (canceled)
 2. A composite device comprising a control portion, adisplay portion, an authentication portion, and a memory portion,wherein the display portion has a function of displaying an image on ascreen, a function of detecting a touch on the screen, and a function ofobtaining first fingerprint data of a finger touching the screen,wherein the authentication portion has a function of executing userauthentication processing, wherein the memory portion has a function ofretaining second fingerprint data, wherein the control portion has: afunction of bringing a system into an unlocked state when theauthentication portion authenticates a user; and a function of comparingthe first fingerprint data and the second fingerprint data when thedisplay portion detects a touch, and bringing the system into a lockedstate in the case where the first fingerprint data and the secondfingerprint data do not match, wherein the display portion comprises: alight-emitting element and a light-receiving element over a substrate;and a light-blocking layer over the light-emitting element and thelight-receiving element, wherein a first opening of the light-blockinglayer overlaps with the light-emitting element, and wherein a secondopening of the light-blocking layer overlaps with the light-receivingelement.
 3. (canceled)
 4. The composite device according to claim 2,wherein the light-emitting element has a stacked-layer structure inwhich a first electrode, a light-emitting layer, and a common electrodeare stacked, wherein the light-receiving element has a stacked-layerstructure in which a second electrode, an active layer, and the commonelectrode are stacked, wherein the light-emitting layer and the activelayer contain different organic compounds from each other, and whereinthe common electrode covers the light-emitting layer and the activelayer.
 5. The composite device according to claim 2, wherein thelight-emitting element has a stacked-layer structure in which a firstelectrode, a common layer, a light-emitting layer, and a commonelectrode are stacked, wherein the light-receiving element has astacked-layer structure in which a second electrode, the common layer,an active layer, and the common electrode are stacked, wherein thelight-emitting layer and the active layer contain different organiccompounds from each other, wherein the common electrode is provided tocover the light-emitting layer and the active layer, and wherein thecommon layer covers the first electrode and the second electrode.
 6. Thecomposite device according to claim 2, wherein the light-emittingelement has a function of emitting visible light, and wherein thelight-receiving element has a function of receiving the visible lightemitted from the light-emitting element.
 7. The composite deviceaccording to claim 2, wherein the light-emitting element has a functionof emitting infrared light, and wherein the light-receiving element hasa function of receiving the infrared light emitted from thelight-emitting element.
 8. (canceled)